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ANAESTHESIA  IN  DENTAL  SURGERY 


Third  Edition,  Revised  and  Enlarged. 

A  TEXT-BOOK  OF 

OPERATIVE     DENTISTRY 

By  Variol's  Authors.     Edited  bj-  C.  N.  Johnsoni 
M.A.,  L.D. S.,  D.D.S.,    Professor  of  Operative  Den- 
tistry  in    the    Chicago   College   of  Dental    Surgery 
Editor  of  the  Dental  Revieiv. 

Royal  8vo.,  762  pp.,  with  618  illustrations.     25s.  net. 
FoLRTH  Edition. 

MODERN      DENTAL      MATERIA 

MEDICA,  PHARMACOLOGY  AND 

THERAPEUTICS 

By  J.  P.  Buckley,  Ph.G.,  D.D.S.,  Professor  and 
Head  of  the  Department  of  Materia  Medica,  Pharma- 
cology and  Therapeutics,  and  formerly  Director  of  the 
Chemical  Laboratories,  Chicago  College  of  Dental 
Surgery. 
Royal  8vo. ,  494  pp.     15s.  net. 

LONDON  :   WILLIAM   HEINEMANN 
(Medical  Books)  LTD. 


ANESTHESIA    IN 
DENTAL     SURGERY 


THOMAS  D.  LUKE,   M.D.,  F.R.C.S.  Ed. 

SURGEON    LIEUT. -COMMANDER,    R.N.    HOSPITAL,    1  EEBLES 

FORMERLY   LECTURER    ON    ANESTHETICS,    EDINBURGH    UNIVERSITY 

AN/ESTHETIST   TO   THE    DENTAL    HOSPITAL,    THE    DEACONESS    HOSPITAL 

AND    INSTRUCTOR    IN    AN.+:STHETICS,    ROYAL    INFIRMARY,    EDINBURGH 

AND 

J.  STUART  ROSS,  M.B.,  F.R.C.S.  Ed. 

LATE    CAPTAIN,    R.A.M.C.    (tC.  \    ON    ACTIVE    SERVICE 

AN/ESTHETIST    TO    THE    DEACONESS    HOSPITAL,    DENTAL    HOSPITAL 

INSTRUCTOR    IN    AN.IJSTHETICS,    ROYAL    INFIRMARY,    EDINBURGH 

AND    LECTURER    IN    ANAESTHETICS,    EDINBURGH    UNIVERSITY 


FOURTH  EDITION 
ILLUSTRATED 


ST.    LOUIS 

C.  V.   MOSBY   COMPANY 

1920 


Printed  in  Great  Britain 


PREFACE  TO  FOURTH  EDITION 

When  the  publishers  early  in  spring  last  year 
called  for  a  further  edition  of  this  work  one  of  the 
writers  was  away  in  the  Eastern  field  of  war,  and, 
after  returning  for  a  brief  spell,  was  again  called 
away,  but  this  time  to  the  Western  front.  The 
bulk  of  the  preparation  has  therefore  fallen  on 
*^  the  senior  partner."  Since  the  return  of  his 
collaborator  time  has  been  available,  however,  to 
incorporate  under  ^*  sequences "  some  of  the 
experience  in  nitrous  oxide  and  oxygen  gained 
and  extended  in  war  hospital  work. 

The  main  structure  of  the  volume  has  largely 
remained  as  before,  but  a  chapter  on  ether  and 
chloroform  added,  largely  doing  away  with  the 
necessity  of  reference  to  other  manuals. 

It  is  hoped  that  the  value  of  the  work  has 
thereby  been  enhanced. 

Fifteen  years  ago  when  the  idea  of  the  book, 
the  first  of  its  kind,  was  conceived,  it  was  refused 
by  more  than  one  publisher  on  the  ground  that 
there  was  '*  no  field."  The  fact  that  we  are  still 
running  and  several  kindred  volumes  have  since 

V 


vi        PREFACE  TO  FOURTH  EDITION 

appeared  again  goes  to  prove  that  even  publishers 
may  make  mistakes  ! 

Our  thanks  are  again  due  to  Major  Guy  for 
material  help  in  matters  in  which  he  has  such 
wide  experience  and  takes  such  deep  interest. 

We  are  also  indebted  to  various  manufacturers 
for  the  loan  of  blocks  for  illustrations,  which  have 
been  purposely  restricted  in  number,  only  the 
principal  types  of  apparatus  being  figured.  For 
elaborations  the  reader  is  referred  to  the  excellent 
catalogues  published  by  the  various  manufacturers. 

T.  D,  L. 

J.  S.  R. 
April  1 6,  191 9. 


PREFACE  TO  SECOND  EDITION 

The  progress  made  in  anaesthetic  methods  during 
the  past  two  years  has  necessitated  considerable 
alteration  in  the  text  of  the  previous  edition  of 
this  little  work.  Our  knowledge  of  the  advan- 
tages and  the  drawbacks  of  ethyl  chloride  has 
been  greatly  increased  during  that  period,  and 
the  section  on  this  anaesthetic  has  been  rewritten 
in  its  entirety.  The  growing  popularity  of  various 
forms  of  local  anaesthetics  has  led  the  author  to 
introduce  a  great  deal  of  new  matter  on  this  most 
interesting  subject.  A  special  chapter  has  been 
devoted  to  the  much-debated  question — How  far 
is  the  L.D.S.  diplomate  entitled  to  administer 
the  various  anaesthetics  ?  The  author  has  con- 
sidered it  best  to  discuss  chloroform  in  the  appen- 
dix, for  although  the  use  of  this  drug  in  dental 
surgery  still  obtains,  unfortunately,  in  certain 
districts,  it  cannot  be  considered  as  having  a  place 
in  modern  operative  dentistry.  Opportunity  has 
been  taken  to  make  various  little  alterations  and 
improvements  suggested  by  kind  reviewers  and 
others. 

vii 


viii      PREFACE  TO  SECOND  EDITION 

The  author  desires  to  express  his  great  indebted- 
ness to  Dr.  Sauvez,  of  L'£cole  Dentaire,  Paris, 
for  kind  permission  to  allow  him  to  translate 
portions  of  Dr.  Sauvez'  monograph,  '  L'Anesthesie 
locale  pour  I'extraction  des  dents,'  and  incor- 
porate them  in  the  section  on  Local  Anaesthesia. 
Dr.  Sauvez'  almost  unique  experience  of  upwards 
of  20,000  cases  of  extraction  under  local  anaes- 
thetics entities  this  section  to  consideration  which 
the  author  would  be  unable  to  claim  for  it  were  it 
merely  based  on  his  own  experience  of  analgesics. 

The  author  desires  to  acknowledge  the  help 
which  he  has  derived  in  writing  the  chapter  on 
the  choice  of  the  anaesthetic  from  a  most  ad- 
mirable paper  on  the  subject  by  Mr.  \Mlliam  Guy, 
the  text  of  which  has  been  freely  quoted.  He  is 
a.lso  very  much  indebted  to  Mr.  \V.  J.  Stuart, 
M.A.,  F.R.C.S.,  for  the  great  care  with  which  he 
has  so  kindly  gone  over  the  proof-sheets. 

Thanks  are  also  due  to  Messrs.  Barth  and  Co., 

Claudius  Ash  and  Co.,  Elliot  and  Co.,  and  other 

instrument-manufacturers,     for     kindly     lending 

electros  for  purposes  of  illustration. 

T.  D.  L. 

Edinburgh, 

December,   1905. 


COiNTENTS 

CHAPTER  I'AGE 

I.   THE   HISTORY   OF  ANAESTHESIA    -                -                -  I 

II.    THE   CHOICE   OF   THE    ANAESTHETIC           -                -  23 

III.  NITROUS   OXIDE     -  -  -  -  "43 

IV.  ETHYL   CHLORIDE                  -                -                -                "79 
V.    ETHER          ■                 -                -                -                -                -  94 

VI.    CHLOROFORM   AND   OBJECTIONS   TO    ITS   USE      -  I03 

VII.    SEQUENCES   AND   COMBINATIONS                 -                -  1 29 

VIII.   THE   USE   OF   LOCAL   ANAESTHESIA              -                -  T72 

IX.  THE   ACCIDENTS   OF  ANESTHESIA              -                -  2l8 

X.  THE    L.D.S.     DIPLOMA    AND    THE     ADMINISTRA- 

TION  OF   ANAESTHETICS              -                -                -  228 

APPENDIX  -..-.-  236 

INDEX           ---.-.  240 


IX 


LIST  OF  ILLUSTRATIONS 

FIG.  PAGE 

1.  braine's  tongue  forceps       -             -             -  36 

2.  heister's  mouth-wedge          -             -             -  36 

3.  Ferguson's  gag            -            -            -            -  36 

4.  vulcanite  props          -             -             -            -  37 

5.  telescopic  prop           -             -             -             -  37 

6.  Hewitt's  props             -             -            -            -  37 

7.  nitrous  oxide  cylinder,  angle  pattern    -  50 

8.  nitrous  oxide  cylinder,  ordinary  pattern  50 

9.  earth's     NgO     APPARATUS,     WITH     FACE-PIECE, 

THREE-WAY    TAP,     THREE-GALLON    BAG,    AND 
CYLINDERS       -  -  -  -  "53 

10.  earth's  THREE-WAY  STOP-COCK  AND  FACE-PIECE  54 

11.  guy's  ARRANGEMENT  FOR  NITROUS   OXIDE           -  57 

12.  PATERSON'S    APPARATUS  -  -  "73 

13.  DIAGRAMMATIC    REPRESENTATION    OF  NERVOUS 

MECHANISM    OF   PUPIL                 .                  _                  .  108 

14.  HEWITT'S    GAS    AND    OXYGEN    APPARATUS               -  1 33 

15.  HEWITT'S      GAS      AND      OXYGEN      STOP-COCK      IN 

PIECES                 -                  -                  -                  -                  -  I3<^' 

16.  CROSS-SECTION    OF   HEWITT's   NgO   AND   OXYGEN 

BAG     -                  -                  -                  -                  -             .    -  139 

xi 


xii  LIST  OF  ILLUSTRATIONS 

FIG.  rAGE 

I-],    guy's  ETHYL  CHLORIDE  INHALER               -                 -  I52 

18.  GAS    AND    ETHER    APPARATUS       -                  -                  -  161 

19.  guy's  arrangement  for  gas  and  ETHER  •         -  I66 

20.  SYRINGE      FOR      LOCAL      ANESTHESIA       (MODEL 

SIMILAR    TO    PRAVATZ)  _  _  -       189 

21.  SECOND     OR    THIRD     UPPER      MOLAR     (VERTICAL 

SECTION)  -----       208 

22.  second   or   third   lower   molar    (vertical 

section)  -  -  -  -     209 


CHAPTER  I 
THE  HISTORY  OF  ANESTHESIA 

Pioneers  of  Anesthetics. 

Nitrous  Oxide. 

Joseph  Priestley  (England)  -  -  -  1776 

Humphry  Davy  ,,  -  -  -  1800 

Horace  Wells,*  CoUyer,  Colton,  Riggs,*  Evans* 

(U.S.A.),  Bert  (France)  -  -  -  1844 

Ethyl  Chloride. 

Heyf elder  -  -  -  -  -  -  1848 

B.  W.  Richardson  .  .  .  .  1867 

Carlson      ------  1896 

McCardie,  Luke     -----  1900 

Sulphuric  Ether. 
M.   Faraday  .  .  -  .  -     1818 

W.  T.  G.  Morton*  (on  himself  and  on  Eben.  H. 

Frost,  at  Boston,  U.S.A.)       -  -  -     1846 

'  Before  whom,  in  all  time,  surgery  was  agony. 
Since  whom  Science  has  control  of  pain.' 

J.  C.  Warren  (on  Gilbert  Abbot,  20,  painter, 
single),  Long,  Jackson,  Ha^^vard,  Bigelow, 
Boot,*  Robinson,*  Listen,  Buchanan,  Longet, 
John  Snow,  Simpson,  Bernard,  Clover  -     1846 

Chloroform. 
James  Young  Simpson      .  -  -  -     1847 

Guthrie,  Soubeiran,  Liebig  -  -  -     181 3 

Dumas       ------     1834 

Associated  with  Waldie,  Flour  ens,  G.  Keith, 
M.  Duncan,  Snow,  Nunneley,  James  Arnott. 

The  extraction  of  teeth  has  from  the  earliest  times 
been  looked  upon  as  a  most  painful  and  trying 

*  Dentists. 


2      ANAESTHESIA  IN  DENTAt  SURGERY 

procedure.  It  has  become  proverbial,  for  do  we 
not  say,  when  speaking  of  a  loss  of  a  very  painful 
nature  befalling  a  person,  '  That  is  an  eye-tooth'? 
During  the  Dark  Ages,  in  the  dungeons  of  feudal 
Barons,  offending  serfs  and  persons  of  even  higher 
class  had  their  ears  and  tongues  and  teeth  removed 
as  a  punishment  and  torture;  and  we  are,  we 
believe,  not  without  record  of  similar  proceedings 
in  the  chambers  of  the  Inquisition. 

There  is  thus  ample  historical  evidence,  did  we 
require  it,  to  prove  that  the  forcible  evulsion  of 
our  organs  of  mastication  is  accompanied  by 
such  a  degree  of  pain  as  to  put  it  in  the  category 
of  torture. 

Accordingly,  when  civilization  dawned  upon  us, 
and  our  digestive  organs  became  simultaneously 
impaired,  painful  affections  of  the  teeth  arose, 
calling  for  their  removal  on  purely  humanitarian 
grounds,  at  first  by  any  good  Samaritan,  but  later 
by  a  special  class  of  men,  who  became  known  as 
*  dentists,'  which  has  evolved  itself  into  the  dental 
profession  of  the  present  day. 

Called  upon  to  constantly  carry  out  this  ex- 
ceedingly painful  operation  on  their  fellow-men, 
women,  and  children,  it  is  not  to  be  wondered  at 
that  some  of  the  profession,  perhaps  endowed 
with  a  greater  love  of  their  fellows  than  others 
and  a  spirit  of  research,  set  themselves  to  find 


THE  HISTORY  OF  ANAESTHESIA        3 

some  substance  capable  of  allaying  or  completely 
abolishing  the  suffering  which  they  were  un- 
avoidably causing.  Such  men  were  Horace  Wells, 
Morton,  Riggs,  and  Evans,  the  pioneers  of  anaes- 
thesia in  dental  surgery. 

The  Discovery"  and  Demonstration   of  the 
Anaesthetic  Properties  of  Nitrous  Oxide. 

A  romance  could  be  written  about  nitrous  oxide, 
which  Joseph  Priestley  discovered  as  a  chemical 
compound  in  1776.     He  was  given  to  inhaling  - 
all  sorts  of  vapours;  he  was  the  first  to  inhale 
oxygen,  and,  of  course,  he  inhaled  nitrous  oxide. 

It  is,  however,  to  Humphry  Davy-  who  began 
life  as  an  apprentice  to  Mr.  Borlase,  a  medical 
man  in  Bodmin,  Cornwall,  and  who  afterwards 
went  to  be  an  assistant  in  his  pneumatic  establish- 
ment at  Bristol  to  Dr.  Beddoes — ^that  we  owe  the 
remarkable  researches  on  this  substance,  carried 
out  for  a  period  of  two  years,  and  published  in 
1800,  when  Davy  was  only  twenty-two.  With 
nitrous  oxide  Davy  experimented  on  plants, 
animals,  and  men,  among  the  last  being  the  poets 
Coleridge  and  Southey. 

It  was  in  1799  he  first  inhaled  gas  himself, 
'when  cutting  one  of  the  unlucky  denies  sapienticB.' 
After  three  or  four  doses  of  nitrous  oxide  the  pain, 
which  was  very  severe,  diminished.     In  1810  he 


4     ANESTHESIA  IN  DENTAL  SURGERY 

published  an  account  of  his  observations  on  nitrous 
oxide.  Nothing,  however,  which  could  be  desig- 
nated conclusive  in  its  relation  to  surgery  re- 
sulted from  Davy's  work.  He  merely  remarked 
that  '  nitrous  oxide  ay  probably  be  used  with 
advantage  during  surgical  operations.'  The  sur- 
gical profession  of  his  day,  however,  were  sceptical, 
and  did  not  think  the  thing  worthy  of  their 
attention. 

The  modern  practice  of  anaesthesia,  though  it 
may  have  been  benefited  indirectly  by  these 
experiments  and  observations,  was  not  the  im- 
mediate outcome  of  them;  it  originated  to  a  large 
extent  independently,  and  nearly  half  a  century 
passed  by  before  anyone  attempted  to  utilize 
nitrous  oxide  for  anaesthetic  purposes. 

The  Introduction  of  Nitrous  Oxide  into 
General  Use. 

One  winter's  night  in  December,  1844,  a  number 
of  the  inhabitants  of  Hartford,  Connecticut,  U.S.A., 
were  assembled  to  hear  a  lecture  on  the  '  Chem- 
istry of  Nitrous  Oxide  and  Other  Gases  '  by  Dr. 
Colton,  a  well-known  popular  lecturer.  In  addi- 
tion to  describing  their  constitution  and  properties, 
he  tried  the  effect  of  the  inhalation  of  the  first- 
named  gas  on  some  of  the  audience. 

Among  the  people  present  were  Horace  Wells 


THE  HISTORY  OF  AN^STHESL\       5 

and  his  friend  John  Riggs,  both  dentists  of  the 
city.  They  were  astonished  to  see  that  one  of 
the  persons  who  inhaled  the  gas  apparently  felt 
no  pain  from  a  severe  injury  he  sustained  to  one 
of  his  legs  while  capering  about  the  hall  when 
partially  recovered  from  its  influence. 

Wells  was  so  impressed  with  this  fact  that  on 
the  followdng  day  he  begged  Dr.  Colton  to  allow 
him  to  inhale  some  of  the  gas,  and  while  under 
its  influence  he  had  one  of  his  molars  extracted 
quite  painlessly.  On  regaining  consciousness  and 
realizing  what  had  been  done,  he  exclaimed,  'A 
new  era  in  tooth-pulling  !'  Wells  was  so  favour- 
ably impressed  with  his  own  experience  that  he 
immediately  proceeded  to  give  the  gas  to  his  own 
patients,  and  did  so  to  more  than  a  dozen  with 
complete  success.  Elated  with  his  good  fortune, 
he  readily  obtained  leave  to  make  a  pubhc  demon- 
stration of  the  method  of  employing  gas  at  Massa- 
chusetts General  Hospital.  Unfortunately,  the 
bag  and  face-piece  were  removed  too  soon,  and 
in  the  extraction  of  the  tooth  the  patient  uttered 
a  piercing  cry.  The  audience,  already  inclined 
to  be  sceptical,  hissed  and  hooted  loudly,  and 
Wells  was  laughed  at  as  an  ignorant  pretender. 
Being  a  modest  and  rather  sensitive  man,  he  felt 
the  insult  deeply,  and  went  home  mortified  and 
disgusted.     Both  he  and  Riggs  continued  to  use 


6     ANESTHESIA  IN  DENTAL  SURGERY 

the  gas  in  their  private  practice,  but  never  again 
attempted  a  pubHc  demonstration.  His  claims 
to  being  the  discoverer  of  modern  angesthesia  were 
ignored,  and,  indeed,  we  are  only  now  beginning 
to  do  his  memory  justice. 

He  never  attempted  to  make  a  secret  of  his 
discovery,  nor  to  use  it  for  selfish  ends. 

His  failure  to  convince  the  public  of  the  genuine 
nature  of  his  discovery,  and  to  bring  the  gas  into 
general  use,  so  preyed  on  his  mind  that  in  a  few 
years  he  fell  ill  and  retired  from  his  profession. 
He  gradually  became  more  and  more  unsettled 
in  his  mind,  and  finally  made  an  end  to  himself 
in  a  pathetically  appropriate  manner  by  inhaling 
ether  to  excess  in  January,  1848. 

A  handsome  monument,  with  a  statue  of  Wells, 
has  been  erected  at  Hartford,  and  ofi  it  is  the 
following  legend: 

HORACE  WELLS, 

WHO    DISCOVERED    ANESTHESIA, 

Dec.  loth,  1844.' 

With  Wells,  for  the  time  being,  the  use  of  nitrous 
oxide  as  an  anaesthetic  died  out,  and  the  discovery 
was  again  in  danger  of  being  lost. 

Dr.  Colton  for  some  years  tried  his  utmost  to 
bring  it  into  general  use,  but  his  efforts  were  quite 
futile  until  1863,  when  he  succeeded  in  getting 
a  few  dentists  to  try  it. 


THE  HISTORY  OF  ANAESTHESIA        7 

After  this  it  was  largely  employed  by  the  denta  1 
profession  in  U.S.A.,  and  in  1867  Colton  came  to 
Paris  to  read  a  paper  on  the  gas,  recording  upwards 
of  20,000  administrations  without  a  single  mishap. 

The  Paris  faculty  were  not  enthusiastic,  but 
in  the  spring  of  1868  Dr.  Evans,  a  very  fashion- 
able American  dentist  resident  in  Paris,  came  to 
London,  and  most  successfully  demonstrated  the 
usefulness  of  nitrous  oxide  before  the  staff  of  the 
Dental  Hospital,  so  that  since  then  it  has  come 
into  universal  use. 

The  Discovery  and  Demonstration  of  the 
Anesthetic  Properties  of  Ether. 

In  18 18  Michael  Faraday  found  that  the  effects 
following  the  inhalation  of  sulphuric  ether  were 
like  those  produced  by  nitrous  oxide,  and  Sir 
Thomas  Watson  recorded  how  his  patient,  Lady 
Martin,  felt  '  as  if.  going'  to  heaven  in  a  most 
heavenly  way  '  when  inhaling  it  for  some  chest 
affection. 

A  year  later  William  T.  Morton  was  bom  in 
Charlton,  Massachusetts.  In  1843  he  qualified 
as  a  dentist  and  M.D.,  and  entered  into  a  suc- 
cessful practice  in  Baltimore.  Fired  with  the 
same  ambition  as  his  partner,  Horace  Wells,  he 
made  attempts  to  extract  teeth  painlessly  wath  the 
assistance    of    drugs    and    even    hypnotism.     In 


8      ANAESTHESIA  IN  DENTAL  SURGERY 

December,   1844,  after  Wells'  failure  with  N2O, 
he  wisely  abandoned  this  agent,  and  investigated 
another  which  promised  better  results.     He  first 
tried  chloric  ether,  which,  as  we  shall  find  later, 
was   the   substance   Simpson   started   with,    but 
failing  to  get  good  results,  and  at  the  suggestion 
of  Jackson,  a  very  skilful  chemist  in  Boston,  he 
proceeded  to  try  the  effect  of  sulphuric  ether. 
His  first  experiments  were  made  on  animals,  and 
were  so  encouraging  that  he  beheved  he  had  at 
last  found  the  desired  agent,  provided  the  effect 
on  human  beings  corresponded  with  that  on  dumb 
creatures.     He  boldly  made  experiments  on  him- 
self,   and  on  September  30,  1846,  inhaled  ether 
from  a  handkerchief  while  shut  up  in  a  room  and 
seated  in  his  own  operating  chair.     He  speedily 
lost  consciousness,  and  in  seven  or  eight  minutes 
awoke  in  the  possession  of  one  of  the  greatest 
discoveries  that  had  ever  been  revealed  to  suffer- 
ing humanity.     We  can  picture  the  man  gradually 
awakening  in  his  chair,  first  to  the  consciousness 
of  his  surroundings,  and  then  to  the  consciousness 
of  his  great  achievement. 

First  Use  of  Ether  in  General  Surgery. 

On  October  16,  1846,  the  first  surgical  operation 
was  performed  under  ether.  The  scene  of  this 
memorable  event  was  the  Massachusetts  General 


THE  HISTORY  OF  ANAESTHESIA        9 

Hospital,  Boston,  U.S.A.  Early  in  October  of 
that  year  Morton  called  on  the  senior  surgeon  of 
the  hospital,  Dr.  Collins  Warren,  and  asked  that 
a  means  of  preventing  pain  in  operation  which  he 
professed  to  have  discovered  might  be  tried  in  a 
surgical  case.  Warren,  having  made  inquiries  as 
to  the  method  proposed  and  its  freedom  from 
danger,  invited  Morton  to  put  it  to  the  test  on 
Friday,  October  16.  On  the  eventful  morning  a 
large  number  of  doctors  assembled  in  the  theatre. 
Morton  was  somewhat  late,  having  been  detained 
by  some  difficulty  in  getting  a  suitable  inhaler. 
The  spectators,  sceptical  enough  to  begin  with, 
not  unnaturally  became  still  more  so  when  it 
appeared  as  if  the  champion  of  the  new  invention 
dared  not  show  his  face  in  the  lists.  After  waiting 
fifteen  minutes,  Dr.  Warren  said  with  significant 
emphasis:  '  Dr.  Morton  has  not  yet  arrived;  1 
presume  he  is  otherwise  engaged.'  The  remark 
was  followed  by  a  derisive  laugh,  and  Warren  was 
on  the  point  of  commencing  the  operation  when 
Morton  entered  the  theatre.  His  reception  was 
the  reverse  of  encouraging,  Warren  saying  to  him 
coldly:  '  Well,  sir,  your  patient  is  ready.'  The 
young  dentist  proceeded  to  administer  the  ether, 
and  in  a  few  minutes  the  patient  was  unconscious, 
whereupon  Morton  said  quietly  to  Warren :  '  Your 
patient  is  ready,  sir.'     The  surgeon's  knife  did  not 


10    ANi^STHESIA  IN  DENTAL  SURGERY 

awaken  the  patient  from  the  deep  sleep  into  which 
he  had  been  passed,  and  the  spectators  looked 
on  \vith  wonder  deepening  into  stupefaction. 
When  the  operation  was  oyer,  Dr.  Warren  said  in 
a  solemn  voice:  '  Gentlemen,  this  is  no  humbug  !' 
The  news  soon  spread  to  Europe,  and  the  first 
administration  of  ether  to  induce  anaesthesia  in 
England  took  place  on  December  19,  1846,  at 
24,  Gower  Street,  London,  the  house  of  Dr.  Booth, 
to  whom  the  news  of  Morton's  discovery  was  com- 
municated by  Dr.  Bigelow,  of  Boston.  On  the 
22nd  of  the  same  month  Liston  amputated  a  limb 
under  ether  in  the  University  College  Hospital, 
and  so  intense  was  the  emotion  of  the  great 
surgeon  on  this  occasion  that,  when  he  turned 
to  address  the  spectators  after  the  operation,  he 
could  hardly  speak. 

Failure  of  Morton  to  patent  Ether,  and 
HIS  Death. 

Morton  endeavoured  to  keep  the  nature  of  his 
discovery  secret,  and  to  patent  it  under  the  name 
of  'Letheon.'  In  this,  however,  he  failed,  and  the 
exact  nature  of  the  agency  was  only  kept  secret 
for  a  very  short  time.  The  characteristic  smell 
of  ether,  so  famihar  to  all  the  medical  profession 
even  at  that  time,  soon  betrayed  its  character. 

Morton  cannot  be  said  to  have  derived  much 


THE  HISTORY  OF  ANESTHESIA      ii 

benefit  from  his  discovery  himself.  He  certainly 
received  several  honours  and  presents,  but  his 
fruitless  endeavours  to  obtain  State  recognition 
of  a  monetary  nature,  together  with  prolonged 
squabbles  and  controversies  concerning  his  dis- 
covery, worried  him  into  a  state  of  ill-health,  and 
very  soon  into  an  early  grave. 

The  Invention  of  a  Suitable  Inhaler 
FOR  Ether. 

Joseph  Thomas  Clover  was  born  at  Aylsham, 
Norfolk,  in  1825.  After  being  apprenticed  to  a 
Norwich  surgeon,  he  entered  University  College, 
London,  where  he  distinguished  himself  as  a 
student.  In  1853  he  began  practice  in  London, 
and  became  an  F.R.C.S.  His  natural  inclina- 
tions were  in  the  direction  of  surgical  practice, 
but  repeated  attacks  of  ill-health  made  him  con- 
fine his  attention  to  anaesthetics.  It  has  been 
said  of  him  that  it  was  a  matter  of  doubt  whether 
the  art  of  surgery  lost  or  anaesthesia  gained  the 
more  by  this.  He  was  a  man  full  of  ingenuity  and 
resource.  His  inventions  were  numerous,  and  he 
was  a  pioneer  in  the  modern  art  of  anaesthesia. 
His  name  will  be  perpetuated  by  his  ether  inhaler, 
which  since  he  brought  it  out  in  1877  has  always 
been,  facile  princeps,  the  best  apparatus  with 
which  to  administer  ether. 


12    ANAESTHESIA  IN  DENTAL  SURCxERY 

The  Introduction  of  Chloroform. 

While  the  discoverer  of  ether  was  wasting  his 
time  and  money  in  dispute  concerning  priority, 
and  Wells  was  dying  from  chagrin  and  inaction, 
a  bolder  and  higher  type  of  man  than  either  had 
taken  up  the  work  where  they  had  left  it,  with  the 
high  object  of  pursuing  it  until  he  had  for  ever 
established  the  benefit  to  humanity  which  he 
recognized  in  it.  This  man  was  James  Young 
Simpson.  He  was  born  at  Bathgate,  in  W^est 
Lothian,  in  1811.  He  entered  the  University  of 
Edinburgh  in  1828,  where  he  had  a  very  distin- 
guished career  as  a  student,  and  took  his  M.D. 
degree  in  1832.  In  1840  he  was  appointed  to  the 
Chair  of  Midwifery  after  a  severe  struggle.  Placed 
in  this  position  at  the  age  of  twenty-nine,  Simpson 
soon  showed  himself  highly  qualified  for  it.  His 
lecture-room  was  thronged  by  eager  students. 
His  fame  quickly  spread,  and  patients  came  to 
him  from  every  part  of  the  world.  He  was  one 
of  the  first  to  call  attention  to  the  evils  of 
'hospitalism,'  and  he  suggested  that  a  separate 
system  should  be  adopted  for  patients,  instead  of 
aggregating  them  in  crowds  in  disease-tainted 
wards.  \\'hen  anaesthesia  came  before  the  world, 
Simpson  at  once  gave  his  mind  to  the  subject. 
He  was  the  first  (January,  1847)  to  apply  ether  to 


THE  HISTORY  OF  ANESTHESIA       13 

the  mitigation  of  the  pains  of  childbirth.  Not 
being  quite  satisfied  with  that  agent,  for  want  of 
proper  apparatus  for  its  administration,  he  set  to 
work  to  discover  some  other  anaesthetic  free  from 
what  he  considered  its  drawbacks. 

Dangerous  Experiments  with  Chloroform. 

He  tried  a  number  of  different  substances  on 
himself,  and  more  than  once  came  near  falHng  a 
martyr  to  his  zeal  for  knowledge.  At  last,  acting 
on  a  hint  from  David  Waldie,  a  Liverpool  pharma- 
cist, he  tried  chloroform.  He  was  not  aware  that 
early  in  1847  a  French  chemist — Flourens — had 
drawn  attention  to  its  effect  on  animals,  or  he 
would  not  have  put  away  untried  the  first  specimen 
sent  him,  as  it  appeared  to  him  heavy  and  non- 
volatile, and  seemed  unlikely  to  be  an  efficacious 
anaesthetic  by  inhalation. 

However,  late  one  evening  early  in  November, 
1847,  ^^  returning  home  after  a  heavy  day's 
labour,  Simpson  and  his  two  friends  and  assistants, 
Drs.  Matthews  Duncan  and  George  Keith  (who  is 
still  ahve),  sat  down  to  their  somewhat  hazardous 
experiments  in  Simpson's  dining-room  in  Queen 
Street,  Edinburgh.  After  inhaling  several  sub- 
stances without  much  effect,  it  occurred  to  him 
to  try  the  neglected  specimen  of  chloroform.  All 
three  charged  their  tumblers  with  the  drug,  and 


14    ANESTHESIA  IN  DENTAL  SURGERY 

began  to  inhale  it.  Very  soon  an  unwonted 
hilarity  seized  the  party;  they  became  bright- 
eyed  and  very  loquacious,  expressing  their  high 
approval  of  the  aroma  of  the  fluid. 

Their  conversation  was  of  quite  unusual  intelli- 
gence, and  quite  charmed  the  friends  who  were 
watching  their  experiments.  But  suddenly  their 
voices  became  louder,  their  expressions  exclama- 
tory, then  unintelligible.  A  moment  more  and 
all  was  quiet,  and  then  there  was  a  crash. 

On  awakening,  Simpson's  first  perception  was 
mental.  '  This  is  better  and  far  stronger  than 
ether,'  he  remarked.  He  then  noted  the  fact  that 
he  and  his  two  colleagues  were  prostrate  on  the 
floor.  Dr.  Duncan,  with  his  eyes  staring  and  his 
jaw  dropped,  was  snoring  in  an  alarming  manner, 
while  Dr.  Keith,  partially  awakened,  was  making 
vigorous  attempts  to  kick  over  the  supper  table  ! 
In  a  few  minutes  all  three  completely  regained 
their  consciousness  and  seats,  and  each  expressed 
his  delight  with  the  new  agent,  which  they  again 
repeatedly  inhaled. 

The  following  morning  Mr.  Duncan,  of  Duncan 
and  Flockhart,  was  pressed  into  their  service  to 
prepare  a  large  supply  of  tlie  drug,  and  Simpson 
made  an  immediate  trial  of  it  in  his  midwifery 
practice,  with  such  success  that  on  November  lo, 
1847,    he    read    before    the    Medico-Chirurgical 


THE  HISTORY  OF  ANAESTHESIA      15 

Society  of  Edinburgh  a  paper  entitled  '  Notice 
of  a  New  Anaesthetic  Agent  as  a  Substitute  for 
Sulphuric  Ether.' 

Professor  MiUer  sent  for  Simpson  a  few  days 
after  the  discovery  of  chloroform  to  ask  him  to 
give  it  to  a  patient  on  whom  he  was  about  to 
perform  a  major  operation.  Simpson  was,  as  luck 
would  have  it,  prevented  from  attending,  and 
!yliller  began  the  operation  without  him.  At  the 
first  cut  of  the  knife  the  patient  fainted  and  died. 

Had  chloroform  been  administered,  one  can 
readily  imagine  what  a  blow  this  untoward  event 
would  have  been  to  Simpson  and  to  the  cause  of 
anaesthesia. 

Subsequently,  however,  he  gave  it  with  great 
success  to  patients  of  Professor  Miller  and  other 
of  his  colleagues,  while  in  his  own  obstetric  prac- 
tice he  used  it  as  a  matter  of  routine,  and  there 
is  no  doubt  that  the  kudos  he  gained  among  the 
fair  sex  from  being  the  first  to  mitigate  the  pains 
of  labour  added  vastly  to  his  already  growing 
reputation. 

Chloroform  soon  came  into  general  use  in  this 
country  in  place  of  ether,  and  the  word  itself 
became  so  common  in  the  vernacular  that  the 
people  began  to  recognize  it  as  synonymous  with 
and  more  expressive  than  an  anaesthetic.  It  may 
have  been   this   fact   that   led   Simpson   in   the 


1 6    ANESTHESIA  IN  DENTAL  SURGERY 

'  Encyclopaedia  Britannica  *  to  deal  with  the  sub- 
ject of  anaesthesia  under  the  heading  '  Chloroform, ' 
but  a  less  charitable  interpretation  was  placed  on 
his  conduct  by  our  American  cousins.  There  can 
be  no  doubt,  however,  that  to  Simpson  belongs 
not  only  the  honour  of  introducing  chloroform, 
but  the  merit  of  popularizing  anaesthesia  both 
with  the  profession  and  with  the  pubHc.  His 
energetic  advocacy  bore  down  all  the  opposition 
that  ignorance,  superstition,  prejudice,  and  scien- 
tific jealousy  mustered  against  it.  His  name  will 
long  hve,  not  only  as  the  introducer  of  chloroform, 
but  as  the  reformer  of  obstetric  medicine,  which 
he  found  the  despised  art  and  left  an  honoured 
science. 

The  idea  prevailed  for  some  time  that  CHCI3 
was  absolutely  safe,  but  the  death  of  a  young 
woman  named  Hannah  Greener,  on  January  28, 
1848,  at  Alloa,  while  being  operated  on  for  an 
ovarian  tumour,  Simpson  himself  acting  as  chloro- 
formist,  soon  showed  that  it  was  an  erroneous  one. 
From  time  to  time  similar  casualties  occurred, 
and  it  soon  became  obvious  that,  whatever  advan- 
tages the  new  system  of  inducing  insensibility 
might  possess,  the  administration  of  chloroform 
was  by  no  means  without  grave  risks  to  Kfe. 

As  death  after  death  was  reported,  every  con- 
ceivable and  inconceivable  theory  was  advanced 


THE  HISTORY  OF  ANESTHESIA       17 

to  explain  them.  The  most  deplorable  ignorance, 
however,  prevailed,  and  several  years  went  by 
before  any  satisfactory  Hght  was  thrown  on  their 
causation. 

The  Introduction  of  Ethyl  Chloride  as  a 
General  Anaesthetic. 

The  career  of  ethyl  chloride  as  a  general  anaes- 
thetic has  been  almost  as  chequered  as  that  of 
nitrous  oxide,  for  it  has  taken  upwards  of  half  a 
century  to  estabhsh  its  position  and  gain  the  con- 
fidence of  the  medical  and  dental  professions. 

In  1848  Heyf elder  first  employed  the  drug  to 
induce  general  anaesthesia  in  the  human  subject. 
For  a  number  of  years  after  that,  however,  ethyl 
chloride  remained  entirely  in  desuetude,  although 
several  observers  commented  favourably  on  its 
value.  In  1867  B.  W.  Richardson  experimented 
with  it,  and  found  it  "  a  good  and  safe  anaesthetic '" ' ; 
but  his  remarks  do  not  seem  to  have  attracted  the 
notice  of  the  profession,  and  we  do  not  find  any 
record  of  the  practical  use  of  this  drug  for  a  period 
of  nearly  thirty  years  after  this.  In  1896  Carlson, 
the  Director  of  the  Dental  Institute  in  Gothenberg, 
showed  that  in  certain  cases  where  local  analgesia 
of  the  gums  was  produced  by  means  of  the  ethyl 
chloride  spray,  the  patient  became  quite  uncon- 


1 8    ANAESTHESIA  IN  DENTAL  SURGERY 

scious.     He  rightly  concluded  that  this  was  due 
to  inhalation  of  the  ethyl  chloride  vapour. 

Thiesing  Billeter  and  other  Continental  surgeons 
and  dentists  then  employed  it  as  a  general  anaes- 
thetic with  good  results,  and  during  the  next  few 
years  several  thousand  cases  were  recorded,  and 
favourably  commented  on  in  the  foreign  medical 
and  dental  journals. 

In  1902  McCardie  of  Birmingham  began  to  use 
the  drug,  and  in  March  of  that  year  pubhshed  an 
article  in  the  Lancet  drawing  attention  to  its 
value  as  a  general  anaesthetic  agent.  Subse- 
quently he  pubhshed  several  other  papers  with 
series  of  cases,  and  it  was  primarily  due  to  his 
advocacy  that  ethyl  chloride  was  taken  up  in  this 
country. 

About  the  same  time  demonstrations  of  an 
anaesthetic  nostrum  known  as  '  somnoform  ' 
(consisting  for  the  most  part  of  ethyl  chloride) 
were  given  at  various  dental  hospitals  throughout 
the  country,  and  there  is  no  doubt  that  these 
attracted  to  a  great  extent  the  attention  of  the 
dental  profession  to  the  matter.  The  market  was 
speedily  flooded  with  all  kinds  of  proprietary 
preparations  under  fanciful  names,  but  actually 
consisting  of  ethyl  chloride  and  nothing  else, 
while  in  a  short  time  inhalers  innumerable,  suit- 
able  and   unsuitable,    were   introduced   for   ad- 


THE  HISTORY  OF  ANAESTHESIA      19 

ministering  the  drug.  Ethyl  chloride  was,  for 
some  four  years  (1901-1905)  administered  broad- 
cast by  all  and  sundry,  and  this  would  constitute  a 
most  trying  test  for  any  anaesthetic  whatever; 
yet  comparatively  few  deaths  have  been  actually 
recorded — about  a  score — though  there  can  be 
little  doubt  that  some  more  have  occurred  which 
have  not  been  brought  to  light.  Be  that  as  it 
may,  one  can  have  no  doubt  that  in  ethyl  chloride 
we  have  a  most  valuable  anaesthetic  agent  for 
dental  surgery. 

Anesthetic  Apparatus. 

Improvements  and  Modifications  of  Inhalers. — ■ 
In  the  early  days  inhalers  and  apparatus  used 
in  connection  with  anaesthetics  were  certainly 
either  conspicuous  by  their  absence  or  elementary 
in  the  extreme.  Now  the  pendulum  has  swung  the 
other  way,  and  the  variety  is  bewildering  in  its 
immensity.  A  glance  over  any  instrument- 
maker's  catalogue  in  the  last  ten  years  in  this 
section  really  gives  food  for  astonishment,  as  there 
appears  to  be  hardly  an  anaesthetist  who  has  .not 
'  modified  '  a  previously  existing  inhaler,  if  he 
has  not  actually  brought  out  quite  a  new  type 
under  his  own  name.  Turn  we  to  American  books 
and  catalogues,  and  the  position  is  much  the  same. 
We  are  as  grieved  to  see  that  distinctly  septic  types 


20    ANESTHESIA  IN  DENTAL  SURGERY 

remain,  such  as  the  Hyderabad  cone  of  leather  and 
felt,  as  we  are  to  observe  later  types  involving  an 
electric  motor  to  drive  them  and  possibly  a  taxi- 
cab  to  take  them  around  from  one  case  to  another  ! 
We  trust  we  may  hurt  no  one's  feelings;  we 
admit  that  one  of  us  at  least  has  in  past  years 
yielded  to  the  temptation  to  allow  his  name  to  be 
attached  to  a  type  of  inhaler  from  the  sale  of  which 
the  maker  got  the  profit,  leaving  such  honour  and 
glory  as  may  have  been  deserved  to  the  designer. 
But  is  it  not  time  to  call  a  halt  ?     Frankly  our 
opinion  is  that  since  Clover  invented  his  closed 
inhaler  no  worker  in  this  field  has  in  basic  principle 
added  anything  very  noteworthy  to  our  arma- 
mentarium, if  we  except  the  late  Sir  Frederick 
Hewitt — a  man   whose   modesty   and   charm   of 
character    was    only    equalled    by    his    extreme 
originality  and  enthusiasm  for  the  field  of  work 
he  adopted. 

The  wide  bore  is  certainly  an  advance,  if  not 
indispensable — a  really  skilled  anaesthetist  will 
do  almost  as  good  work  with  a  well-made  Clover. 
Hewitt's  work  with  gas  and  oxygen  is  note- 
worthy, and  his  apparatus  adapted  to  the  nasal 
method  has  been  perfected  by  Bellamy  Gardner. 

Every  anaesthetist  worth  his  salt  will  from  time 
to  time  Hke  to  make  some  experiments,  and  a  new 
apparatus  made  by  himself  or  a  friendly  rival  has 


THE  HISTORY  OF  ANESTHESIA      21 

its  attractions.  He  will  end,  probably,  in  discard- 
ing most  of  them,  fill  a  small  attic  with  perishing 
rubber  and  dull  nickel  plate,  and  recall  with 
regret  the  many  guineas  w^hich  he  has  laid  out 
in  vain.  Poeta  nascitur,  non  fit — and  the  anaes- 
thetist is  the  same,  with  this  primary  postulate: 
it  cannot  be  too  strongly  emphasized  how  very 
secondary  a  part  '  apparatus  '  play  in  all  anaes- 
thesia. 

It  is  on  the  eye  judgment  and  skill  of  the  ad- 
ministrator, developed  by  years  of  training  and 
experience,  that  the  safety  of  the  patient  and 
comfort  of  the  operator  depend. 

The  older  anaesthetist  develops  a  wholesome 
conservatism  without  necessarily  getting  out  of 
date.  His  methods  and  apparatus  are  few  and 
simple  usually;  he  rehes  rather  on  the  tactus 
eruditus,  and  the  valves,  stop-cocks,  and  thermo- 
phores, are  mere  details,  sometimes  easily  dis- 
pensed with. 

It  must  be  pointed  out  further  that  the  time  has 
now  come  in  everyone's  interest  for  standardiza- 
tion of  apparatus  on  certain  broad  lines,  just  as 
nuts  and  screws  are  standardized  by  engineers. 
Medical  men  and  dental  surgeons  have  everything 
to  gain  by  this,  and  '  the  Trade  '  are  not  against  it. 
Recently,  in  conversation  with  the  manager  of  a 
large  dental  emporium,  the  subject  was  raised  by 


22    ANESTHESIA  IN  DENTAL  SURGERY 

one  of  the  authors,  and  received  strong  support 
and  approval. 

Such  people  are  in  business  for  profit,  naturally, 
and  if  they  are  constantly  making  or  stocking  new 
apparatus  the  sale  of  which  is  uncertain,  they  have 
to  try  and  make  the  price  of  one  cover  the  possible 
loss  on  several  never  sold. 


CHAPTER  II 

THE  CHOICE  OF  THE  ANAESTHETIC  FOR 
DENTAL  OPERATIONS 

There  are  four  factors  to  be  considered  in  making 
the  choice,  viz. — (i)  The  patient,  (2)  the  opera- 
tion, (3)  the  operator,  and  (4)  the  person  who 
administers  the  anaesthetic. 

I.  The  Patient. 

The  age  of  the  patient  is  the  primary  considera- 
tion, and  with  children  and  old  people  we  have 
dealt  fully  elsewhere.  For  young  healthy  adults 
and  middle-aged  people  nitrous  oxide  gas  is  best 
adapted  if  a  brief  anaesthesia  only  be  required. 

Sex  has  Httle  influence  on  our  choice,  but  the 
position  in  Hfe  of  the  patient  has  a  considerable 
influence  on  behaviour  under  an  anaesthetic. 
Thus,  if  we  exclude  hysterical  women  and  alco- 
holics of  both  sexes,  members  of  the  upper  and 
middle  classes  take  anaesthetics  quietly,  generally 
speaking,  and  regain  consciousness  without  any 
undue  display  of  the  emotions. 

23 


24    ANAESTHESIA  IN  DENTAL  SURGERY 

'  The   masses,    whose   emotions   and   instincts 
are  undisciplined,  and  who  have  never  practised 
any  degree   of  self-control,   or  experienced  any 
control,    parental,    sacerdotal,    or    magisterial — 
who  are,  in  short,  uneducated,  though  they  may 
have    passed    through    a    course    of    elementary 
instruction — will  often  resist,  scream,  swear,  kick, 
and  otherwise  misconduct  themselves  during  the 
administration    and    after    the    recovery.     Alco- 
holics, loose  women,  and  football-players,  when 
gas  and  ether  or  gas  and  ethyl  chloride  are  being 
administered  to  them,  should  be  brought  more 
fully  under  the  gas  before  the  ethyl  chloride  or 
ether  is  introduced  than  would  be  necessary  in 
the  case  of  less  excitable  patients.     The  state  of 
the  patient's  health  is  important,  but  does  not 
require  very  long  consideration  here,  because  if 
the  patient  is  fit  for  the  operation  he  is  fit  for  the 
anaesthetic.     No  doubt  there  are  many  conditions 
in  which  the  administration  of  the  anaesthetic  is 
attended  with  grave  risks,  and  must  give  rise  to 
anxiety.     This  may  be   truthfully   said,   for  in- 
stance, of  acute  intestinal  obstruction,  depressed 
fracture  of  the  skull,  the  terminal  stages  of  ex- 
hausting diseases,  or  of  dyspnoea  from  the  narrow- 
ing or  obstruction  of  respiratory  passages,  by  the 
presence  or  pressure  of  growths.     But  patients 
exhibiting  these   conditions   are   seldom  sent  to 


THE  CHOICE  OF  THE  ANAESTHETIC     25 

have  their  teeth  extracted  under  anaesthetics. 
There  are  many  conditions  which  call  for  care 
and  skill  on  the  part  of  the  anaesthetist.  Ad- 
vanced atheroma,  chronic  bronchitis,  Bright's 
disease,  advanced  phthisis  pulmonalis,  valvular 
disease  of  the  heart,  especially  with  failing  com- 
pensation, aortic  aneurism,  pernicious  anaemia, 
and  diseases  of  the  central  nervous  system  are  a 
few  of  these  '  (Guy). 

2.  The  Operation. 

If  one  or  two  teeth  only  require  to  be  extracted, 
nitrous  oxide  is  the  best  anaesthetic,  unless  there 
be  some  contra-indication,  from  being  most  usually 
available. 

If  there  be  five  or  six  teeth  of  uncertain  difh- 
culty  to  extract,  the  choice  wiU  he  between  con- 
tinuous gas  administration  by  the  nasal  method 
and  a  mixture  of  nitrous  oxide  oxygen  and  ethyl 
chloride. 

If  there  be  a  greater  number  of  teeth  or  a  very 
difficult  tooth,  such  as  an  impacted  wisdom,  then 
gas  and  ether  or  ethyl  chloride  and  ether  sequence 
should  be  used. 

3.  The  Operator. 

Where  the  operator  unfortunately  requires  to 
fulfil  the  double  function  of  operator  and  anaes- 


26    ANESTHESIA  IN  DENTAL  SURGERY 

thetist,  he  has  to  calculate  the  time  he  will  need, 
and  gauge  his  own  dexterity  as  an  extractor.  On 
the  other  hand,  if,  as  should  always  be  the  case,  a 
separate  individual  act  as  anaesthetist,  his  proper 
course  is  to  ask  the  dental  surgeon  who  is  to 
operate  what  time  he  thinks  it  likely  he  will  re- 
quire, and  then  choose  his  anaesthetic  accordingly. 
The  anaesthetics  at  his  disposal  are  the  following : 
Nitrous  oxide  gas,  ethyl  chloride,  gas  and  ethyl 
chloride  sequence,  nitrous  oxide  (nasal  method), 
gas  and  ether  sequence,  ethyl  chloride  and  ether 
sequence,  ethyl  chloride  and  C.E.  sequence,  C.E. 
and  ether  sequence,  and  local  anaesthesia.  The 
available  anaesthesia  with  these  will  be  somewhat 
as  f  oUows : 

Nitrous  oxide    . .          .  .  .  •  35  seconds, 

,,           ,,     and  eth.  chlor.  .  .  90  to  120  seconds. 

„           ,,     and  oxygen  .  .  90  to  120  seconds. 

„           ,,     (nasal  method)  .  .  i  to  5  minutes. 

,,           ,,     and  ether  .  .  i  to  10  minutes. 

Ethyl  chloride  .  .          .  .  .  .  i  to  2  minutes. 

Ethyl  chloride  and  ether  .  .  i  to  10  minutes. 

Ethyl  chloride  and  C.E.  .  .  2  to  5  minutes. 

C.E.  and  ether  sequence  .  .  3  to  10  minutes  or  ad  lib. 

Local  anaesthesia           . .  .  .  As  required. 

4.  The  Anesthetist. 

The  person  responsible  for  the  anaesthetic  will 
be  influenced  by  various  considerations.  In  a 
dentist's  room  or  at  a  hospital,  gas  or  gas  and  ether 


THE  CHOICE  OF  THE  ANAESTHETIC     27 

will  receive  his  first  consideration,  but  if  the  opera- 
tion is  to  be  done  at  the  patient's  house,  and 
possibly  at  a  distance,  the  greater  portability  of 
ethyl  chloride  will  influence  him  in  its  favour. 
We  are  now  supposing  that  the  administrator  is 
familiar  with  all  the  anaesthetics  which  we  have 
enumerated,  but,  unfortunately,  this  is  frequently 
very  far  from  the  case;  indeed,  when  the  indi- 
vidual in  question  is  a  country  practitioner, 
his  experience  is  restricted  in  most  cases  to  two 
anaesthetics,  generally  chloroform  and  ether;  too 
often,  north  of  the  Tweed,  to  chloroform  alone. 
Guy  says:  '  In  the  latter  case,  I  think  it  is  the 
duty  of  the  dentist  to  state  very  plainly  to  the 
doctor  his  preference  for  some  other  anaesthetic 
than  chloroform,  to  insist  on  the  operation  taking 
place  elsewhere  than  at  his  house  (if  chloroform  be 
used),  and  to  make  it  clear  that  he  disclaims  and  is 
absolved  from  any  responsibility  for  any  untoward 
result.'  With  this  expression  of  opinion  the 
authors  are  entirely  in  accord.  Elsewhere  their 
views  are  stated  on  this  question  in  extenso. 

Anesthetics  in  Special  Cases. 

Children. — Children  of  tender  years  are  by  no 
means  good  subjects  for  nitrous  oxide.  It  is 
often  w^ell-nigh  impossible  to  maintain  a  satisfac- 
tory  anaesthesia   for   anything  but   the   shortest 


28    ANAESTHESIA  IN  DENTAL  SURGERY 

dental  operation  in  a  child  under  seven  years  of 
age  by  means  of  this  anaesthetic,  the  difficulty 
increasing  the  younger  the  child  is.  In  the  first 
place,  we  have  all  a  dread  of  the  unknown,  and 
in  children  this  is  especially  the  case;  the  appa- 
ratus looks  formidable,  and  may  terrify  the  little 
patient. 

Again,  it  is  difficult  for  the  dentist  to  operate 
so  rapidly  as  on  an  adult,  for  the  mouth  is  small 
and  the  forceps  large,  while  there  may  be  cyanosis 
and  spasm,  jactitation,  and  not  uncommonly 
screaming  on  the  patient's  part.  In  this  connec- 
tion, it  is  often  very  difficult  to  persuade  the 
friends  who  may  be  present  that  the  child  has  felt 
nothing,  for  the  crying  and  jerking  of  the  body 
and  limbs  seem  to  the  uninitiated  to  be  the  out- 
ward and  visible  manifestation  of  a  painful  sensa- 
tion. 

The  degree  of  success  which  is  attained  with  this 
class  of  patient  will  largely  depend  on  the  tact  and 
patience  of  the  person  conducting  the  administra- 
tion. His  patience  and  powers  of  persuasion  will 
in  some  cases  be  strained  to  the  utmost,  often  not 
more  by  the  child,  however,  than  by  a  foolish 
and  doting  parent.  It  is  useless  to  lose  one's 
temper  in  any  case,  and  perseverance  in  this,  as 
in  most  things,  will  win  the  day. 

If  the  insertion  of  the  mouth-prop  be  much  ob- 


THE  CHOICE  OF  THE  ANAESTHETIC     29 

jected  to,  the  administration  may  be  commenced 
and  a  prop  slipped  in  when  the  sensibilities  have 
become  somewhat  duller,  or  a  mouth-opener  be 
used  when  complete  anaesthesia  has  been 
estabhshed. 

Breaths  of  air  should  be  given,  one  to  every  five 
respirations  w^hen  nitrous  oxide  is  administered, 
so  that  cyanosis  may  be  lessened  and  anaesthesia 
prolonged.  For  the  extraction  of  the  four  six- 
year-old  molars  Paterson's  apparatus  for  the 
nasal  administration  of  gas  is  most  valuable,  but 
unless  the  administrator  is  famihar  with  it,  ethyl 
chloride  or  gas  and  ethyl  chloride  should  be  used. 

Patients  who  are  advanced  in  Years. — Patients 
over  sixty  years  of  age,  if  in  good  health,  usually 
take  nitrous  oxide  well;  they  pass  quickly  under 
its  influence,  and  though  cyanosis  is  rather  marked, 
the  anaesthesia  is  long  in  duration,  and  profound 
compared  wdth  young  adults.  The  addition  of  a 
little  oxygen  to  the  nitrous  oxide  will  in  many 
cases  be  found  advantageous.  In  deahng  with 
such  patients,  however,  it  must  be  remembered 
that  they  are  frequently  the  subjects  of  senile 
changes  in  the  way  of  thickened  and  brittle 
arteries,  feeble  hearts  and  diminished  respiratory 
power. 

Special  watchfulness  is  needed,  and  the  possi- 
bility of  apoplexy,  if  nitrous  oxide  be  pushed,  is 
to  be  borne  in  mind. 


30    ANAESTHESIA  IN  DENTAL  SURGERY 

The  presence  of  '  winter  cough '  or  chronic  bron- 
chitis should  be  inquired  after,  and,  if  the  patient 
suffers  in  this  way,  ether  should  be  avoided  or 
given  sparingly.  The  gas  and  ethyl  chloride 
sequence,  or  ethyl  chloride  alone,  is  well  suited  to 
people  of  advanced  years. 

Heart  Disease. — Although  nitrous  oxide  is  by 
no  means  contra-indicated  in  cardiac  disease,  all 
such  cases  should  be  treated  with  additional  care, 
and  the  anaesthetic  be  given  by  an  expert  anaes- 
thetist or  in  the  presence  and  with  the  help  of 
a  fully-quahfied  medical  man.  To  satisfy  the 
patient,  at  least,  it  is  well  that  the  physician 
should  feel  the  pulse  at  the  wrist  before  starting 
the  anaesthetic,  and  in  some  cases  the  preliminary 
administration  of  a  httle  brandy  or  other  alcohoHc 
stimulant  is  of  value.  The  cyanosis  often  becomes 
marked  at  an  early  period  of  the  inhalation,  and 
the  pulse  (which  should  be  kept  under  observation 
throughout  the  administration)  becomes  slower; 
if  any  sign  of  intermittence  is  noticed,  the  gas 
should  be  immediately  withdrawn.  Ethyl  chlor- 
ide and  ethyl  chloride  and  ether  may  be  given 
with  safety. 

Pulmonary  Disease. — Patients  suffering  from 
any  pulmonary  affection  are  not  good  subjects  for 
any  anaesthetic,  particularly  if  there  be  any  tend- 
ency to  dyspnoea ;  the  emphysematous  and  bron- 


THE  CHOICE  OF  THE  ANESTHETIC     31 

chitic  take  nitrous  oxide  badly,  often  becoming 
intensely  livid,  and  they  may  succumb  from  heart 
failure,  for  their  blood  is  inefhciently  aerated,  and 
the  right  side  of  the  heart  is  already  overloaded. 
Pa*tients  suffering  from  tubercular  disease  of  the 
lungs  also  require  special  consideration  and  careful 
treatment.  When  there  are  large  cavities  in  the 
lungs  in  advanced  years,  the  loss  of  breathing 
space  impedes  the  action  of  the  gas,  while  in  all 
cases  early  and  late  haemoptysis  may  be  brought 
on  by  the  administration  of  nitrous  oxide  and 
ether. 

Further,  if  chloroform  be  given,  these  patients 
often  give  trouble  during  the  anaesthesia,  and 
make  a  bad  recovery,  suffering  from  vomiting, 
and  giving  evidence  of  general  systemic  depression 
for  days. 

If,  therefore,  chloroform  be  employed  for  some 
special  reason,  it  should  be  administered  along 
with  oxygen,  for  this  combination  gives  a  much 
better  type  of  anaesthesia,  and  the  after-effects  are 
usually  very  sHght. 

Unless  this  course  be  adopted,  the  alternative 
one  is,  if  an  extensive  extraction  be  required,  to 
have  several  sittings,  and  to  remove  three  or  four 
teeth  at  a  time  under  gas  and  oxygen  anaesthesia. 
The  necessity  for  these  precautions  should  be  care- 
fully explained  to  the  patient. 


32    AN.ESTHESIA  IN  DENTAL  SURGERY 

Further,  the  greatest  possible  care  should  be 
taken  to  sponge  thoroughly  and  maintain  oral 
asepsis  while  the  gums  are  healing,  so  as  to  prevent 
any  secondary  infection  of  the  lung  of  a  septic 
nature,  which,  if  it  supervened,  would  place  the 
patient  in  a  position  of  great  jeopardy. 

Nervous  Disorders. — 'Epileptic  and  choreiform 
seizures  are  recorded  as  having  been  induced  by 
the  inhalation  of  nitrous  oxide  and  other  anaes- 
thetics. The  author  has  seen  several  such  cases 
when  gas  was  being  administered,  but  they  are 
not  of  sufficiently  frequent  occurrence  to  warrant 
refusing  to  administer  gas  to  persons  who  are 
subject  to  epileptiform  or  choreic  attacks. 

Cases  of  insanity  and  mental  aberration  fol- 
lowing artificial  anaesthesia  have  been  recorded. 
Savage  has  drawn  special  attention  to  this  question 
(British  Medical  Journal,  December  3,  1887).  We 
have  personally  known  of  two  patients  suffering 
from  temporary  delusional  insanity  after  inhaling 
nitrous  oxide. 

Although  on  theoretical  grounds  ether  is  known 
to  tend  to  cerebral  congestion  and  mental  excite- 
ment, there  seems  to  be  no  contra-indication  to  the 
use  of  gas  and  ether,  or  ethyl  chloride  and  ether, 
for  a  brief  anaesthesia  such  as  is  required  for  dental 
work  among  persons  who  are  mentally  afflicted. 
Guy,  w^ho  has  a  large  experience  among  this  class 


THE  CHOICE  OF  THE  ANAESTHETIC    33 

of  patient,  is  of  this  opinion,  and  the  authors  are 
in  agreement  with  him. 

As  regards  hysteria,  women  who  are  not  prone 
to  hysterical  manifestations  not  uncommonly  give 
signs  of  them  when  recovering  from  nitrous  oxide 
or  ethyl  chloride,  and,  of  course,  the  tendency  is 
more  marked  in  '  hysterical  subjects.'  A  little 
tact  and  firmness,  however,  is  all  tha^t  is  necessary 
in  dealing  ith  such  patients.  Their  noisy  lamen- 
tations, and  sometimes  cataleptic  condition,  may 
often  be  very  trying  to  the  busy  dentist.  The 
windows  should  be  opened  wide,  a  wet  towel 
applied  to  the  forehead,  strong  smelling-salts  used, 
while  sympathizing  friends  are  removed  from  the 
room,  and  they  and  the  patient  from  the  house 
as  soon  as  may  be. 

Pregnancy. — Nitrous  oxide  maybe  administered 
with  safety  to  most  patients  up  to  within  a  month 
of  full  term,  but  care  must  be  taken  to  avoid 
pushing  the  gas  and  inducing  marked  clonic  con- 
tractions. If  the  patient  is  very  nervous  and 
anxious  about  the  matter,  or  if  she  is  almost  at 
full  term,  it  will  be  wiser  to  substitute  the  gas  and 
ethyl  chloride  sequence  (or  ethyl  chloride  alone) 
for  nitrous  oxide,  using  every  possible  precaution. 

Alcoholism  and  Drug  Habits. — Patients  who  are 
given  to  the  injudicious  use  of  alcohol,  and  to  the 
use  of  cocaine  and  morphia,  are  disposed  to  be 

3 


34    AN.^STHESIA  IN  DENTAL  SURGERY 

unusually  troublesome  during  artificial  anaesthesia, 
and  it  is  well  to  be  on  one's  guard  in  dealing  with 
them.  With  alcoholic  patients  struggling  is  always 
to  be  expected,  and  may  be  very  violent  and 
troublesome. 

Several  assistants  may  be  required  to  restrain 
the  patient,  and  all  glasses,  mirrors,  jugs,  and  trays 
of  instruments  should  be  placed  in  the  back- 
ground in  case  of  accident. 

In  the  case  of  morphia  maniacs,  especially  if 
they  have  recently  had  an  injection,  quite  a  small 
amount  of  anaesthetic  may  suffice,  and  care  is 
necessary  not  to  push  it  too  far. 

Tobacco  Habit. — It  is  well  known  that  persons 
addicted  to  the  excessive  use  of  tobacco  take 
anaesthetics  badly  as  a  rule.  The  inveterate  pipe- 
smoker  has  hyper trophied  muscles  of  mastication. 
The  mucous  membrane  of  his  nose,  mouth,  and 
pharynx  is  injected  and  often  oedematous;  his 
uvula  is  often  elongated  and  swollen,  resting  on 
the  dorsum  of  the  tongue ;  and  his  air- way  is  thus 
narrowed.  His  mucous  and  salivary  glands  be- 
come larger  and  more  active,  and  hence  the  in- 
creased salivary  secretion.  The  heart  may 
be  dilated  and  sounds  soft;  the  pulse  weak  and 
sometimes  irregular.  Ether  often  seriously  in- 
creases the  injection  and  oedema  of  the  respiratory 
tract,  and  sets  up  a  series  of  spasms,  with  exces- 


THE  CHOICE  OF  THE  ANAESTHETIC     35 

sive  secretion  of  mucus,  etc. ;  after  a  good  deal 
of  coughing,  the  patient  becomes  lightly  anaes- 
thetized, yet  his  face  is  Hvid,  and  he  is  half  choked 
by  the  swollen  mucous  membrane  and  retained 
secretion.  The  pale,  anaemic  youth,  who  smokes 
an  excessive  quantity  of  cigarettes,  besides  posess- 
ing  the  abnormal  respiratory  tract  of  the  pipe- 
smoker,  shows  evidence  of  thickening  and  irrita- 
tion of  the  bronchial  mucous  membrane  caused  by 
inhalation  of  the  smoke,  which  in  all  probability 
n  some  cases  actually  damages  the  lung- tissue. 
In  the  cigarette-smoker,  also,  the  nervous  changes 
are  more  marked  than  in  the  pipe-smoker.  The 
former  is  highly  strung,  nervous,  and  irritable, 
and  is  apt  to  get  fainting  attacks.  The  knee-jerks 
are  increased,  ankle  clonus  sometimes  present, 
and  fine  tremors  of  the  hands  very  obvious. 
When  nitrous  oxide  is  administered  much  is 
needed;  the  breathing  is  shallow  in  character  and 
struggling  of  common  occurrence. 

Ether  causes  great  irritation  of  the  already 
irritated  mucous  membrane  of  the  trachea, 
bronchi,  and  perhaps  even  of  the  alveoh,  and 
probably  spasm  of  the  bronchial  muscular  coats. 
Moist  rales  may  be  heard  over  the  back  and  front 
of  the  luQgs,  Hke  those  of  acute  bronchitis.  The 
induction  of  ether  or  ethyl  chloride  ether  anaes- 
thesia is  often  unpleasant,  and  even  impossible  in 
some  cases. 


36    ANESTHESIA  IN  DENTAL  SURGERY 


FIG.    I. BRAINE'S    tongue   FORCEPS. 


FIG.    2. HEISTER'S    MOUTH-WEDGE. 


FIG.    3. FERGUSON 


THE  CHOICE  OF  THE  ANESTHETIC     37 

If  the  insertion  of  the  mouth-prop  causes  retch- 
ing, as  it  often  does,  this  may  be  overcome  in 
most  cases  by  rinsing  the  mouth  out  \nth  a  weak 


FIG.    4. VULCANITE 

PROPS. 


FIG.  5. TELESCOPIC 

PROP. 


FIG.  6. — Hewitt's  props. 


solution  of  carbolic  acid  (i  :  100).     The  combina- 
tion of  oxygen  with  the  gas  will  greatly  lessen  the 


38    ANAESTHESIA  IN  DENTAL  SURGERY 

cyanosis  and  jactitation.  In  some  cases  the  use 
of  chloroform  and  oxygen  will  be  preferable,  and 
even  necessary,  rather  than  ether.  If  ether  is 
employed,  however,  the  previous  injection  of 
j^  grain  of  atropine  will  be  of  great  use  to  pre- 
vent excessive  secretion. 


Accessory  Apparatus  required  in  Anaesthesia 
FOR  Dental  Operations. 

Among  these  may  be  specially  mentioned  the 
following : 

1.  Instruments  for  opening  the  mouth  and 
keeping  it  open,  such  as  gags  and  props. 

2.  Tongue  forceps. 

3.  Sponge  holders. 

4.  Hypodermic  syringe  and  solution  of  strych- 
nine (i  :  100). 

5.  A  bib  or  apron  for  the  patient,  to  prevent 
soiUng  of  the  clothes. 

6.  Some  sponges  of  coarse  texture,  or  pieces  of 
gauze  which  can  be  rolled  up  to  make  '  swabs.' 
The  'aseptic  tampons,'  tightly  rolled  in  an  out- 
side cover  of  muslin,  are  practically  useless  for 
sponging. 

Of  gags,  there  are  many  kinds.  The  best  one, 
generally  speaking,  for  dental  work  is  that  of 
Ferguson    or   Dudley   Buxton,    with   good   long 


THE  CHOICE  OF  THE  ANAESTHETIC     39 

handles  which  allow  of  a  considerable  amount  of 
purchase.  Croft's  gag  finds  favour  with  some 
people,  but  the  handles  do  not  allow  of  sufficient 
purchase,  if  the  patient  has  a  strong  jaw  or  if 
there  is  any  tendency  to  masseteric  spasm. 

The  essential  points  to  look  to  in  selecting  one 
are  the  length  of  the  handles ;  the  tooth- plates  of 
the  gag  (which  should  come  close  together,  or  lie 
in  the  same  plane  as  in  Buxton's) ;  a  ready  means 
of  fixing  the  gag  in  any  degree  of  extension;  an 
easily- working  joint;  and,  lastly,  good,  all-forged 
blades  throughout.  A  little  dexterity  in  using  a 
gag  is  readily  acquired  when  once  its  mechanism 
is  understood,  and  quickness  of  apphcation  is 
essential  to  its  successful  employment. 

As  regards  mouth-props,  the  most  generally 
useful  are  the  simple  ebony  or  vulcanite  ones, 
with  their  surfaces  padded  with  indiarubber. 
Hewitt's  pattern  and  Gardner's,  both  made  of 
aluminium,  are  good,  but  rather  too  large  for  use 
on  young  children.  Some  men  prefer  to  use 
spring  gags,  such  as  Buck's;  but,  generally  speak- 
ing, these  should  be  avoided,  as  the  spring  is  very 
apt  to  get  out  of  order,  and  sometimes  the  two 
parts  of  the  gag  separate  at  an  awkward  moment. 
Further,  the  adjusting  part  looks,  and  is,  difficult 
to  clean,  so  that  a  fastidious  patient  may  object 
to  using  it.      The  following  are  the  chief  points 


40    ANAESTHESIA  IN  DENTAL  SURGERY 

to  have  regard  to  in  the  selection  of  a  mouth- 
prop  : 

1.  It  should  be  made  of  hard  material,  not 
likely  to  split  or  chip,  so  that  it  may  be  scrubbed 
frequently.  The  dental  surface  should  be  fitted 
with  pads  of  rubber  or  some  non-absorbent  sub- 
stance. 

2.  It  should  be  as  small  as  is  compatible  with 
strength,  or  it  will  be  in  the  operator's  way. 

3.  It  should  be  all  one  piece,  as  joints  are  apt 
to  give  way. 

4.  A  strong  piece  of  catgut,  silk,  or  whipcord 
10  to  12  inches  long  should  be  tied  firmly  round  the 
stem,  and  attached  to  another  prop,  so  as  to  do 
away  with  any  chance  of  the  prop  going  down  the 
patient's  pharynx.  The  string  requires  frequent 
renewing,  as  it  soon  gets  blood-stained  and  soiled. 

A  cork  properly  shaped  with  a  sharp  penknife, 
and  tied  to  a  string,  makes  quite  a  good  emergency 
gag,  but  can  only  be  used  once  or  twice.  A  little 
care  expended  on  the  insertion  of  the  mouth-prop 
well  repays  the  operator.  The  prop  should  always 
lie  quite  straight,  and  be  held  firmly  in  the  bite. 
If  possible,  it  should  never  be  placed  further  for- 
ward than  the  bicuspid  teeth,  or  the  masseteric 
spasm  set  up  during  the  anaesthesia  (if  gas  or  ethyl 
chloride  be  used)  may  be  so  great  as  to  force  out 
one  of  the  incisors  or  canines.     If  it  has  to  be 


THE  CHOICE  OF  THE  ANAESTHETIC    41 

placed  far  forward,  it  should  be  put  between  the 
incisors,  and  a  prop  broad  enough  to  overlap  two 
teeth  should  be  employed. 


Inhalers  recommended  for  Ordinary 
Practice. 

Every  dental  surgeon  or  practitioner  who  is 
often  called  upon  to  help  in  dental  work  will  do 
well  to  provide  himself  with  Earth's  or  Hewitt's 
N2O  apparatus  with  a  three-way  stop-cock  and 
2  or  3  gallon  bag. 

He  will  also  be  wise  to  acquire  an  ether  chamber 
(Clover  or  Hewitt's)  to  fit  the  gas  apparatus. 
The  gas-bag  can  be  used  for  ethyl  chloride,  as 
Hewitt  recommended,  with  an  air-pump  and 
small  tube  of  ethyl  chloride  attached  to  the 
bottom,  or  he  can  use  an  ordinary  Clover  i-gallon 
bag  with  the  hole  in  the  top  of  the  angle-tube,  as 
suggested  by  one  of  the  authors. 

A  Schimmelbusch  mask  is  almost  an  essential 
in  all  anaesthetic  work,  and,  while  not  essential 
by  any  means,  a  Junker  may  be  added  for  use  in 
such  rare  cases  of  dental  work  as  chloroform  may 
be  called  for. 

Anything  more  than  this  is  a  luxury  only 
justified  in  high-class  practice.  The  specialist 
will  often  prefer  to  give  gas  by  Patterson's  method, 


42    AN.ESTHESIA  IN  DENTAL  SURGERY 

or  gas  and  oxygen  as  suggested  by  Bellamy 
Gardner,  but  that  is  work  rather  for  the  trained 
anaesthetist  than  a  practitioner. 

Certainly  it  is  a  moral  impossibility  for  a 
dentist  to  use  either  and  operate  at  the  same 
time. 


CHAPTER  III 

NITROUS  OXIDE 

Nitrous  oxide  is  in  all  respects,  facile  princeps, 
the  basic  anaesthetic  for  the  dental  surgeon.  Pro- 
perly used,  it  is  almost  entirely  free  from  danger, 
and  is  rarely  productive  of  nausea  or  even  tem- 
porary depression  as  after-effects.  By  means  of  it 
about  35  seconds  of  anaesthesia  can  be  obtained, 
in  the  majority  of  cases  in  one  minute,  sufhcient 
time  being  afforded  to  allow  a  dentist  of  ordinary 
dexterity  to  extract  from  one  to  five  teeth  or  more. 
It  is  essential,  however,  and  only  fair  to  the  person 
acting  as  anaesthetist,  for  the  operator  to  have 
everything  in  readiness  for  starting,  before  the 
patient  begins  to  inhale,  so  that  every  second  of 
the  period  of  anaesthesia  may  be  utilized  if 
necessary. 

In  these  days  to  extract  teeth  without  the  use 
of  '  laughing  gas,'  except  in  the  case  of  the  most 
hardy  and  robust  men  and  in  emergencies,  is  little 
short  of  barbarous.  It  is  cruel  to  the  patient, 
and  if  the  subject  is  a  child,  wantonly  so.     Very 

43 


44    ANAESTHESIA  IN  DENTAL  SURGERY 

few  people  can  submit  to  the  operation  without 
some  resistance,  and  though  this  be  involuntary, 
the  operator  is  handicapped  by  it,  and  from 
anxiety  to  be  quick,  the  liability  to  break  a  tooth 
or  portion  of  the  alveolar  plate  is  greatly  increased. 

Nitrous  Oxide  (NgO).     Synonyms:  Protoxide 
OF  Nitrogen,  '  Laughing  Gas,'  or  Gas. 

Nitrous  oxide  gas  is  a  colourless  body,  possess- 
ing a  rather  sweet  taste  and  odour,  and  a  specific 
gravity  of  1-527.  It  is  neutral  in  reaction,  and 
consists  of  nitrogen  and  oxygen  in  chemical  com- 
bination, and  so  differs  from  atmospheric  air, 
which  is  simply  a  mechanical  mixture  of  these 
gases.  Nitrous  oxide  has  been  proved  to  possess 
well-defined  anaesthetic  properties,  and  these  are 
not  due  to  simple  displacement  of  oxygen  in  the 
blood,  or  to  a  partial  asphyxia,  but  to  the  fact  that 
the  gas  enters  into  a  loose  combination  with  the 
hsemoglobin  in  the  red  blood-corpuscles,  and  is 
so  conveyed  to  the  nerve  centres,  on  which  it 
has  a  specific  action. 

It  is  possible  to  hquefy  nitrous  oxide  with  a 
pressure  of  fifty  atmospheres  at  a  temperature 
of  7°  C,  and  the  practical  and  commercial  import- 
ance of  this  Hes  in  the  fact  that  the  gas  can  be 
readily  stored  in  steel  or  iron  bottles,  and  so  con- 
veniently carried  about.     Liquid  nitrous  oxide — 


NITROUS  OXIDE  45 

specific  gravity  -936 — is  colourless  and  mobile, 
and  15  ounces  of  it  will  yield  50  gallons  of  the  gas. 
The  pressure  in  the  cylinders  containing  nitrous 
oxide  often  registers  1,000  pounds  per  square  inch. 
The  gas  undergoes  rapid  expansion  when  heated 
in  any  way,  and  if  this  be  done  incautiously  with- 
out the  valve  being  unscrewed  a  little  so  as  to 
allow  a  slight  escape  of  the  gas,  the  cylinder  may 
burst. 

Under  very  great  pressure  nitrous  oxide  will 
solidify,  and  becomes  white  and  snowlike  in  ap- 
pearance. When  gas-bottles  are  lying  horizon- 
tally, and  the  gas  is  allowed  to  escape  suddenly,  it 
often  assumes  the  solid  form,  especially  on  a  cold 
day,  and  so  blocks  the  outlet.  This  sometimes 
gives  us  the  impression  that  the  bottle  is  empty, 
but  a  few  minutes  later,  when  the  obstructing 
particles  have  melted,  the  gas  escapes  with  a  loud 
explosive  report. 

Nitrous  oxide  is  prepared  by  heating  granulated 
ammonium  nitrate  to  460°  F.  and  collecting  the 
gas  evolved  over  water.  The  process  is  compara- 
tively simple,  and  until  recently  dentists  often 
prepared  their  own  gas.  There  are  a  number  of 
impurities,  however,  which  require  removal,  and, 
unless  this  is  effected,  they  often  give  an  un- 
pleasant and  nauseous  smell  to  the  gas,  and  cause 
irritation  of  the  throat  and  respiratory  passages 


46    ANESTHESIA  IN  DENTAL  SURGERY 

of  the  patient.  Accordingly,  it  is  desirable  to 
procure  gas  only  from  a  reliable  maker  who 
carries  out  the  processes  necessary  for  a  complete 
purification  of  the  gas.  There  is  no  advantage  in 
using  freshly-prepared  gas,  for  when  stored  in 
cylinders  it  keeps  perfectly  well. 

Physiological  x\ction  of  Nitrous  Oxide. 

The  exact  nature  of  the  action  of  the  gas  on 
the  human  organism  was  for  a  long  time  very 
imperfectly  understood,  and  from  the  erroneous 
conception  of  its  action  it  came  to  be  regarded  as 
somewhat  untrustworthy  and  even  unsafe.  It 
was  generally  believed  that  it  displaced  oxygen 
from  the  blood,  and  when  the  tissues  reached  a 
certain  point  of  cellular  asphyxia,  they  lost  their 
power  of  receiving  and  conveying  stimuli.  The 
late  Sir  George  Johnson  actually  contended  that 
the  gas  merely  produced  '  a  beneficial  asphyxia.' 

Though  the  appearance  of  the  patient  under 
nitrous  oxide  may  be  in  some  cases  rather  sugges- 
tive of  asphyxia,  this  is  owing  to  undue  air  de- 
privation, or  some  constitutional  dyscrasia  of  the 
patient,  rather  than  the  actual  effect  of  the  nitrous 
oxide  gas. 

It  is  hardly  necessary  to  say  that  an  anaesthesia 
produced  largely  by  means  of  asphyxia  would  be 
extremely  dangerous,  and  we  know,  both  from 


NITROUS  OXIDE  47 

personal  experience  and  from  the  vast  number  of 
cases  recorded,  that  nitrous  oxide  is  by  a  very  long 
way  the  safest  anaesthetic  we  possess.  Paul  Bert, 
while  recognizing  that  the  gas  had  a  specific  action 
on  the  tissues  in  producing  insensibility,  considered 
that  the  anaesthesia  was  accompanied  by  asphyxial 
phenomena,  due  to  air  exclusion,  which  he  con- 
sidered essential.  Afterwards  he  discovered  that 
anaesthesia  could  be  produced  even  when  air  and 
oxygen  were  mixed  with  the  gas. 

More  recently  Dudley  Buxton,  Hewitt,  and 
Bellamy  Gardner  conclusively  demonstrated 
that: 

1.  Nitrous  oxide  enters  into  loose  combination 
with  the  haemoglobin  of  the  red  blood-corpuscles, 
and  probably  is  so  conveyed  to  the  cells  of  the 
nerve  centres. 

2.  It  exerts  a  specific  action  on  the  central 
nervous  system. 

3.  The  phenomena  of  nitrous  oxide  anaesthesia 
are  totally  distinct  from  those  occurring  in 
asphyxia. 

4.  The  effect  of  the  nitrous  oxide  is  stimulating 
on  the  circulation,  particularly  on  the  heart  itself, 
except  in  so  far  as  the  introduction  of  any  gas  into 
the  pulmonary  circulation,  if  we  exclude  oxygen, 
increases  friction,  and  so  interferes  in  some  degree 
with  the  circulation.     That  a  mixture  of  air  and 


48    ANAESTHESIA  IN  DENTAL  SURGERY 

nitrous  oxide,  with  a  proportion  not  exceeding 
30  per  cent,  of  air,  or  a  mixture  of  NgO  and 
oxygen,  with  not  more  than  12  per  cent,  of  the 
latter,  will  produce  a  reliable  and  efficient  anaes- 
thesia. 

Dudley  Buxton  well  says :  '  Nitrous  oxide 
appears  to  suspend  rather  than  extinguish 
vitahty.' 

Animals  placed  in  irrespirable  gases  become 
convulsed  before  death;  but  when  they  are  made 
to  respire  nitrous  oxide,  their  respiration  simply 
grows  more  and  more  shallow,  and  finally  ceases 
without  any  of  that  besoin  de  respirer  which  is 
elicited  when  simple  oxygen  deprivation  is  prac- 
tised. 

Apparatus  required  in  the  Administration 
OF  Nitrous  Oxide. 

1.  The  cylinders  for  storing  the  gas. 

2.  The  apparatus  used  for  allowing  the  liquefied 
gas  to  expand  and  to  convey  it  to  the  patient's 
respiratory  passages. 

3.  Mouth-openers  (Mason's  gag),  props,  etc. 
Nitrous  oxide,  immediately  after  being  prepared 

and  purified,  is  liquefied  under  very  great  pressure, 
and  stored,  as  before  mentioned,  in  very  strong 
steel  bottles  or  cylinders  of  various  sizes.  Those 
most  commonly  in  use  arc  the  25,  50,  and  100 


NITROUS  OXIDE  49 

gallon  sizes,  weighing  from  3  pounds  7  ounces  to 
about  8  pounds  7  ounces  respectively. 
There  are  two  patterns  of  cyhnder: 

The  Angle  Pattern. 
The  Ordinary  Pattern. 

The  first  named  are  now^  largely  used,  as  they 
are  more  convenient  for  general  purposes. 

The  figures  on  p.  50  illustrate  the  two  bottles. 
At  B  or  B'  is  a  very  powerful  valve  with  the 
end  squared  so  as  to  fit  the  pedal  A  or  A',  by 
means  of  which  the  gas  is  turned  on  and  escapes 
at  the  orifice  C  or  C  into  a  tube  attached  for 
conducting  it  into  the  gas-bag  or  gasometer. 

Formerly  the  bottles  were  made  of  iron,  but 
thev  are  now  made  of  steel,  as  when  so  con- 
structed  they  can  be  made  equally  strong  with 
much  less  metal. 

There  are  a  few  practical  points  worth  mention- 
ing as  regards  storing  of  gas.  When  the  bottles 
arrive  they  should  be  at  once  w^eighed  to  check 
the  weights  noted  on  the  label  fixed  on  the  bottle 
by  the  maker. 

They  should  be  then  stored  in  a  box  or  cup- 
board, where  the  temperature  is  fairly  equable, 
not  near  a  stove  or  fire,  and  not  in  a  place  where 
they  are  likely  to  be  knocked  about  or  to  fall. 
If,  when  a  bottle  is  being  used  for  the  first  time, 

4 


50    ANAESTHESIA  IN  DENTAL  SURGERY 


the  gas  escapes  in  a  slow  and  somewhat  spasmodic 
manner,  the  bottle  is  probably  overfilled,  and 
frozen  particles  of  liquid  gas  have  escaped  into 
the  narrow  exit  and  choked  it.  One  may  be 
mistaken  and  imagine  the  bottle  empty,  and  if 

C 


FIG.    7. ANGLE   PATTERN 

CYLINDER.* 


FIG.  8. ORDINARY  PATTERN 

CYLINDER. 


it  be  put  aside  turned  on,  a  somewhat  alarming 
explosion  will  suddenly  occur.  The  bottle  should 
be  taken  off  the  stand,  and  kept  slightly  turned  on 

*  Messrs.  Earth's  cylinders  are  fitted  with  a  special 
arrangement  to  prevent  moisture  reaching  the  spindle  (B) 
and  causing  corrosion  and  leakage. 


NITROUS  OXIDE  51 

while  warm  water  is  trickled  slowly  over  the  neck 
until  the  gas  comes  fizzing  out. 

If  a  considerable  quantity  of  gas  is  used  at  a 
time,  the  bottle  usually  gets  coated  with  hoar-frost, 
and  then  caution  is  needed  in  handling  it  to  avoid 
a  severe  burn.  It  is  convenient  to  have  two  angle 
bottles  coupled  on  to  a  stand,  and  to  use  the  same 
one  until  empty,  so  that  if  it  becomes  empty 
during  an  administration  the  other  is  always 
ready  and  may  be  turned  on,  while  the  empty  one 
is  replaced  at  a  convenient  opportunity. 

Some  bottles  are  very  stiff  in  starting,  and  it 
is  advisable  to  slightly  loosen  the  valve  with  a 
wrench  before  commencing. 

The  foot-keys  are  made  both  in  brass  lacquered 
and  nickel-plated  steel,  the  latter  being  rather 
neater  and  less  expensive. 

In  using  them,  the  sole  or  heel  of  the  boot,  of  the 
left  leg  usually,  is  firmly  placed  on  the  foot-key, 
and  by  rotating  the  leg  to  the  left  and  outwards 
the  valve  is  opened,  and  vice  versa.  With  a  little 
practice  the  amount  of  gas  escaping  can  be  very 
nicely  regulated. 

After  the  administration  is  over,  great  care  is 
needed  to  see  the  valve  is  very  tightly  screwed 
down,  otherwise  a  very  sUght  escape  may  go  on, 
and  on  the  next  occasion  the  gas-bottle  may  be 
found  completely  emptied. 


52    ANAESTHESIA  IN  DENTAL  SURGERY 

The  gas  may  be  administered  {a)  by  means 
of  a  gasometer,  or  (b)  by  the  modern  nitrous 
oxide  apparatus  as  made  by  Barth  and  Co.,  with 
3-gallon  bag  and  tubing,  three-way  stop-cock, 
and  face-piece,  and  two  50-gallon  gas-bottles 
on  a  stand. 

{a)  The  nitrous  oxide  gasometer  is  really  pre- 
cisely on  the  same  principle  as  that  used  for  the 
storage  of  coal-gas.  It  consists  of  a  metal  reser- 
voir sinking  into  a  tank  of  water,  and  counter- 
poised by  weights  passing  over  pulleys. 

The  gas  is  introduced  into  the  reservoirs  by 
means  of  a  tube  connected  with  a  large  gas-bottle. 
If  a  gasometer  is  used,  it  is  convenient  to  keep  it 
in  the  room  immediately  beneath  the  operating- 
room,  if  possible,  and  by  means  of  the  tube  passed 
through  the  flooring  to  a  stand-pipe  beside  the 
chair  to  keep  up  the  suppty  of  gas.  Or  it  may 
be  kept  in  a  cupboard,  and  moved  out  into  the 
operating-room  on  castors  when  it  is  wanted. 
The  advantages  of  a  gasometer  are  that: 

1.  The  gas  under  a  definite  pressure  is  forced 
continuously  and  evenly  through  the  lubes  and 
face -piece. 

2.  If  the  valve  of  the  gas-bottle  is  not,  or  for 
some  reason  cannot  be,  turned  off  completely, 
there  is  less  waste,  and  the  gas  simply  flows  into 
the  reservoir,  and  remains  there  under  increased 
pressure. 


NITROUS  OXIDE 


53 


The  advantages,  however,  taking  all  things  into 
consideration,  are  quite  overcome  by  the  tendency 
to  get  leaky,  the  clumsy  nature  of  the  apparatus, 
and  the  initial  expense. 


FIG.    9. earth's  N2O  APPARATUS,  WITH  FACE-PIECE, 

THREE-WAY    TAP,    THREE-GALLON    BAG,    AND    CYLINDERS. 

(b)  The  latter  method  seems  to  find  most  favour 
in  the  eyes  of  the  present-day  dentist,  for  the 
apparatus  is  portable,  cheaper  than  a  gasometer, 


54    AN.ESTHESIA  IN  DENTAL  SURGERY 

and.  on  the  whole,  more  economical  of  gas  and 
less  likely  to  get  out  of  order,  while  the  gas  is 
always  inhaled  fresh,  and  anaesthesia  more  satis- 
factory. 

I.  Connecting  the  gas-bottles  with  the  rubber 
tubing  of  the  apparatus  for  administration  is  a 
metal  union  consist'ng  of  a  tapering  nozzle  and 
a  screw-nut  for  fixing  it.     Between  the   two  a 


FIG.    lO. earth's    three-way    STOP-COCK    AND 

FACE-PIECE. 

leather  washer  is  placed  so  as  to  make  the  union 
absolutely  hermetical. 

2.  The  ruT^ber  tubing  between  this  and  the  bag 
is  about  I  inch  in  diameter,  stoutly  made,  and 
about  4  feet  long. 

3.  The  bag  to  which  this  is  attached  is  an  im- 
pervious rubber  bag,  made  of  high  quahty  rubber, 
and  not  too  thick,  the  capacity  being  about 
3  gallons. 


NITROUS  OXIDE  55 

The  best  method  of  attachment  is  a  simple 
viilcanite  tap,  so  that,  if  it  is  desired  to  detach 
the  bag  from  the  tubing,  this  may  be  done, 
and,  by  turning  the  tap,  any  escape  of  gas  is 
prevented. 

To  the  upper  end  of  the  bag  a  three-way  stop- 
cock is  fixed,  fitted  with  valves. 

There  are  three  apertures  in  the  stop-cock:  one 
opening  into  the  gas-bag,  one  opening  into  the 
face-piece,  and  another  opening  to  the  external 
air  directly  or  through  valves,  according  to  the 
position  of  the  indicator.  The  stop-cock  has  three 
arms:  one  communicating  with  the  face -piece; 
the  second  communicating  with  the  gas-bag;  and 
the  third  containing  a  simple  expiratory  flap 
valve. 

At  the  junction  of  the  three  arms  is  situated 
the  actual  tap,  which  also  contains  a  rubber  '  flap  ' 
valve,  and  the  movements  of  the  tap  are  so 
arranged  that  on  turning  it  more  or  less  roimd  we 
obtain : 

(A)  Communication  between  the  face-piece  and 
the  external  air  alone,  the  bag  being  shut  off. 

(B)  Communication  between  the  face-piece 
and  the  gas-bag,  both  valves  working;  or, 
lastly, 

(C)  Communication  between  the  face -piece  and 
the  bag  alone,  both  valves  being  cut  off. 


56    AN.^STHESIA  IN  DENTAL  SURGERY 

Face-pieces  : 

(i)  Leather  and  rubber  sheeting. 

(2)  Compo  and  pad. 

(3)  Compo  and  glycerine. 

(4)  Celluloid  and  metal. 

Whether  the  anaesthetic  be  gas,  ethyl  chloride, 
or  ether,  it  is  equally  important  to  secure  a  good 
face-piece  which  does  not  allow  oi  leakage. 

To  prevent  this  entirely  may  be  a  very  difficult 
matter  if  the  patient  wears  a  large  moustache  or 
a  beard,  but  with  an  ordinary  clean-shaven  face  a 
properly  constructed  face -piece  makes  it  quite 
easy. 

The  face-piece,  despite  the  less  degree  of  asepsis, 
should  be  in  one  piece.  For  those  of  metal  or 
celluloid  with  a  movable  rubber  pad  we  have  no 
preference,  but  quite  the  contrary,  as  leakage  is 
more  likely  to  occur,  and  they  are — the  celluloid 
type,  at  any  rate — more  fragile  and  uncertain. 

In  our  experience  the  best  type  of  face-piece  is 
made  by  Barth  and  Co.,  of  a  solid  basis  of  rubber 
and  leather  compo  with  the  inflatable  pad  fixed 
up  with  some  adhesive  substance. 

This  is  very  strong  and  lasts  a  long  time ;  and 
while  it  cannot  be  boiled,  it  can  be  well  soaked 
in  antiseptic  solution. 

Next  to  that  comes  the  type  with  the  inner  layer 


NITROUS  OXIDE 


57 


of  leather  covered  on  each  side  with  a  layer  of  thin 
sheet-rubber. 

The  shape  is  important.     The  opening  which 


FIG.    II. guy's  arrangement   FOR  NITROUS  OXIDE. 


fits  over  the  patient's  face  should  be  an  oblong 
with  the  greater  breadth  at  the  lower  end.  It 
should  be  neither  round  nor  angular  at  the  sides, 


58    AN.ESTHESIA  IN  DENTAL  SURGERY 

as  one  sometimes  finds  in  foreign  and  cheap 
types. 

The  pad  is  usually  inflated,  but  Arnold  and  Co. 
have  put  a  face -piece  on  the  market  with  the  pad 
filled  with  glycerine,  which  seems  a  good  idea. 

If  the  apparatus  is  not  being  used  fairly  regu- 
larly, the  indiarubber  valves  are  apt  to  dry  and 
curl  up  at  the  edges.  This  can  be  avoided  by 
moistening  them  occasionally  with  a  little  warm 
water  or  weak  carbolic  lotion. 

The  Preparation  of  the  Patient  for 
Nitrous  Oxide. 

Little  or  no  previous  preparation  in  the  way  of 
fasting  is  necessary,  but  the  gas  should  not  be 
inhaled  soon  after  a  fiiQ  meal.  In  all  cases  it  is 
weU  to  allow  two  hours  to  elapse  between  a  meal 
and  the  administration.  Prolonged  fasting  is, 
however,  undesirable,  and,  indeed,  increases  any 
liability  to  fainting. 

In  spite  of  the  extreme  safety  of  nitrous  oxide, 
it  is  distinctly  desirable  for  the  administrator  to 
'  take  stock  '  of  the  patient  before  undertaking 
the  production  of  anaesthesia. 

If  the  patient  looks  fit  and  robust,  the  dentist 
may  merely  remark  that  he  assumes  he  has  good 
health.  If  the  patient  is  pale,  anaemic  or  '  seedy  * 
looking,  he  may  go  a  little  further,  and  inquire 


NITROUS  OXIDE  59 

as  to  any  fainting  fits,  etc.  //  there  seems  any 
doubt  whatever  as  to  the  physical  fitness  of  the 
patient,  the  ordinary  medical  attendant  should  he 
undoubtedly  communicated  with,  and  certainly  if 
such  a  wish  is  expressed,  or  it  seems  in  any  way 
desirable,  his  presence  at  the  proposed  administra- 
tion secured.  This  will  take  much  responsibility 
off  the  shoulders  of  the  dentist  in  any  case,  and 
if  anything  untoward  does  happen,  the  medical 
man  may  afford  valuable  assistance. 

In  most  medical  schools  students  are  now  being 
taught  to  give  gas  along  with  other  anaesthetics, 
so  that  the  practitioner  himself  may  be  able  to 
undertake  the  production  of  anaesthesia. 

It  is  weU,  as  before  mentioned,  especially  when 
dealing  with  young  children,  to  get  the  bladder 
emptied  before  putting  them  in  the  chair,  and 
corsets  should  be  removed  or  unlaced.  The  upper 
buttons  of  a  coat  or  dress  should  be  undone,  and 
collar  or  brooch  removed.  Gloves,  spectacles, 
hat,  and  artificial  teeth  are  also  to  be  removed. 

Patients'  friends  are  usually  better  out  of  the 
operating-room,  but  if  they  or  the  patient  ex- 
pressly desire  it,  they  must  be  allowed  to  remain, 
and  should  be  placed  in  such  a  position  as  not  to 
be  able  to  see  the  patient's  face,  which,  when  he 
or  she  is  fully  under  the  influence  of  gas,  may  be 
far  from  pleasing  in  appearance.     In  connection 


6o    AX.ESTHESIA  IX  DENTAL  SURGERY 

with  the  subject,  it  is  necessary  to  state  that  under 
no  circumstances  should  gas  or  other  anaesthetic 
be  administered  to  a  female  without  the  presence 
of  a  third  party,  preferably  one  of  her  own  sex, 
as  charges  of  criminal  assault,  usually  made  in  all 
good  faith,  are  not  uncommon. 

The  patient  is  now  seated  in  the  chair,  and 
must  be  placed  so  as  to  suit  both  the  require- 
ments of  the  anaesthesia  and  the  operation.  He 
should  be  made  to  sit  well  back  in  the  chair,  the 
legs  uncrossed  and  not  too  much  flexed,  nor 
pressed  firmly  against  the  foot-rest.  This  last  is 
of  special  importance  when  the  patient  is  tall,  as 
opisthotonos,  or  arching  of  the  back,  will  often 
occur  when  he  becomes  unconscious,  so  that  he 
should  be  told  to  place  his  feet  on  the  floor  beside 
the  foot-rest. 

The  head-rest  must  be  brought  well  forward, 
and  fixed  firmly  in  such  a  position  that  the  long 
axis  of  the  patient's  head  is  in  continuation  with 
the  long  axis  of  the  body. 

The  importance  of  loose  clothing  during  anaes- 
thesia-— ^whether  induced  by  gas,  gas  and  oxygen, 
or  ether — is  very  great,  in  order  to  prevent  any 
possible  constriction  of  the  upper  respiratory 
passages,  and  to  allow  complete  expansion  of  the 
hmgs  by  diaphragmatic  action. 

If  there  are  tightly-laced  corsets  or  waistbands. 


NITROUS  OXIDE  6t 

fuU  descent  of  the  diaphragm  is  interfered  with, 
abdominal  breaths  cannot  be  taken,  and  the  rapid 
exchange  of  the  air  in  the  lungs  for  the  anaesthetic 
gas  cannot  be  effected.  If  the  operator  particu- 
larly wishes  the  head  somewhat  thrown  back,  this 
should  be  effected  after  the  anaesthesia  has  been 
established. 

Before  starting,  the  patient  is  asked  to  clasp  his 
hands,  or  to  firmly  grip  the  arm  of  the  chair  {not 
of  the  operator  !),  and  this  is  of  especial  value 
when  dealing  with  nervous  people. 

Bellamy  Gardner  uses  a  belt  or  strap  to  hold 
the  patient  up  in  the  chair. 

The  Effects  produced  by  the  Inhalation  of 
Nitrous  Oxide. 

It  is  customary  to  divide  the  process  of  inducing 
and  establishing  anaesthesia  into  three  stages :  • 

First  Stage. — The  gas  being  turned  on,  the 
patient  is  at  once  conscious  of  the  sweetish  but 
not  unpleasant  taste  which  it  possesses. 

A  feeling  of  warmth  on  the  lips  and  an  in- 
describable though  not  unpleasant  numbness  in 
the  limbs  is  noted,  while  the  patient  has  an  irre- 
sistible desire  to  breathe  more  quickly  and  deeply. 
He  then  experiences  a  curious  feehng  of  expansion 
and  '  thrilling  '  throughout  the  body.  Ringing  in 
the  ears  is  common. 


62    ANAESTHESIA  IN  DENTAL  SURGERY 

Consciousness  is  lost,  however,  in  twenty  to 
thirty  seconds,  almost  before  the  patient  has  time 
to  define  his  sensations,  and  the  respirations 
deepen  and  become  more  regular. 

The  pulse  is  fuller,  firmer,  and  somewhat 
quickened.  The  power  of  hearing  persists  during 
this  stage,  and,  indeed,  may  become  hyperacute, 
so  that  silence  is  very  desirable. 

Second  Stage. — The  patient  is  now  unconscious, 
but  not  fully  anaesthetized.  Movement  of  the 
arms  and  legs  is  common,  and  this  may  be  of  an 
almost  methodical  nature — e.g.,  beating  rhythmi- 
cally on  the  floor  with  the  feet,  or  moving  the  arms 
as  in  romng.  These  movements  are  known  as 
'  occupation  spasms.'  Excitement  is  not  usual 
if  the  gas  be  properly  administered  and  air  duly 
excluded.  Vivid  dreams  are  common,  and  may 
be  rendered  extremely  unpleasant  by  commencing 
any  operative  procedure  at  this  stage.  Further,  if 
an  extraction  be  attempted,  shouting  and  excite- 
ment will  almost  invariably  occur.  Erotic  dreams 
and  sensations  are  by  no  means  uncommon,  both 
at  this  stage  and  also  later,  when  the  patient  is 
emerging  from  the  anaesthesia. 

Respiration  is  deeper  and  quicker  than  normal, 
and  is  regular  in  character.  The  pulse  is  full  and 
more  rapid  than  usual;  the  conjunctival  reflex  is 
still  present.     The  pupils  are  gradually  dilating, 


NITROUS  OXIDE  63 

and  the  complexion  is  growing  dusky,  the  change 
being  especially  marked  in  people  of  fair  com- 
plexion. The  eyehds  often  twitch  and  become 
slightly  separated. 

Third  Stage. — The  respiration  now  loses  its 
regular  character,  and  a  curious  and  characteristic 
'snorting'  sound  or  stertor  becomes  noticeable. 
This  is  owing  to  some  obstruction  of  the  air-way, 
due  to  spasmodic  contraction  of  the  elevators  of 
the  larynx  raising  it  towards  the  epiglottis  and  base 
of  the  tongue.  This  stertor  will  be  always  more 
marked  if  the  patient's  head  is  at  aU  extended, 
from  the  head-rest  of  the  chair  being  too  far  back. 

The  pulse  is  more  rapid  in  character,  running 
up  to  100  or  120  in  the  minute,  but  is  somewhat 
less  robust  than  in  the  second  stage,  and  this  is 
probably  due  to  less  blood  reaching  the  left  side 
of  the  heart. 

The  muscles  may  be  quite  relaxed,  and  the 
arms  faU  Hmply  if  raised  by  the  anaesthetist,  but 
some  rigidity  due  to  clonic  or  tonic  spasm  is  more 
common  if  the  gas  is  at  all  pushed.  The  spas- 
modic contractions  are  first  noticed  in  the  fingers, 
but  they  spread  through  the  whole  body,  and  may 
be  so  violent  as  to  jerk  the  patient  out  of  the  chair. 
These  movements  are  commonly  known  as 
jactitation. 

The   facial   muscles   are   in   some    cases   more 


64    ANESTHESIA  IN  DENTAL  SURGERY 

affected  than  any,  and  the  appearance  of  the 
patient  is  then  usually  extremely  unpleasant. 
Sometimes  the  erector  spince  muscles  are  chiefly 
affected,  and  then  the  phenomenon  opisthotonos  is 
seen,  the  patient's  back  forming  a  complete  arch, 
while  he  is  merely  supported  by  his  heels  on  the 
foot-board  and  his  head  on  the  head-rest.  This 
very  awkward  development  usually  disappears  on 
lightehing  the  anaesthesia  by  giving  air  or  oxygen. 

]\Iicturition  and  the  passage  of  flatus,  or  even 
fasces,  may  occur  in  this  stage,  particularly  in 
children.  Accordingly,  it  is  well  to  get  a  young 
patient  to  empty  his  bladder  before  giving  nitrous 
oxide. 

The  pupil  is  now  usually  well  dilated,  conjunc- 
tival reflex  gone,  but  this  is  not  always  the  case. 

The  facial  expression  is  usually  considerably 
distorted,  the  eyeballs  rotate  in  an  unpleasant 
manner,  and  fat  people  of  the  apoplectic  type 
become  markedly  cyanosed. 

The  Administration. 

Before  adjusting  the  face -piece,  it  is  necessary 
in  the  large  majority  of  cases  to  insert  a  mouth- 
prop  (such  as  described  previously).  Care  must 
be  taken  that  it  lies  quite  straight  and  firmly  in  the 
bite.  It  should,  if  possible,  never  be  placed 
further  forward  than  the  bicuspid  teeth,  or  the 


NITROUS  OXIDE  65 

masseteric  spasm  set  up  during  anaesthesia  may 
be  so  great  as  to  force  the  incisors  or  canines  out. 
If  it  be  far  forward,  place  it  between  the  incisors, 
and  see  that  the  prop  is  sufficiently  broad  to 
impinge  on  the  surface  of  the  two  teeth. 

In  some  cases  where  there  is  an  alveolar  abscess 
it  may  be  quite  impossible  to  open  the  mouth 
sufficiently  to  insert  a  prop.  In  such  cases  the 
administration  may  be  gone  on  with,  and,  when 
the  patient  is  under,  the  mouth  may  be  opened 
by  means  of  a  wooden  wedge  or  Heister's  screw- 
gag. 

The  face-piece  having  been  adjusted  with  the 
pointer  of  the  stop-cock  turned  to  *  Air,'  the 
patient  is  instructed  to  breathe  quietly  to  and  fro 
(not  to  take  deep  breaths),  and  the  pointer  turned 
to  '  Valves.'  The  gas  is  now  breathed  in  from  the 
bag  through  the  inspiratory  valve  into  the  mouth 
and  lungs  of  the  patient,  and  expired,  mixed  with 
COg,  etc.,  through  the  expiratory  valve. 

This  may  be  continued  for  eight  or  ten  breaths, 
when  the  pointer  may  be  turned  right  on  to  '  No 
valves,'  and  to  and  from  breathing  be  permitted 
until  anaesthesia  is  induced.  The  bag  should  not 
be  allowed  to  become  distended,  but  be  kept  full, 
so  that  the  gas  is  admini-.tered  rather  above  the 
atmospheric  pressure. 

Care  must  be  taken  throughout  to  avoid  any 


66    ANAESTHESIA  IN  DENTAL  SURGERY 

leakage  around  the  face-piece,  which  is  particu- 
larly apt  to  occur  around  the  upper  part. 

It  may  be  necessary  in  some  cases  to  exercise 
a  little  pressure  here  by  means  of  the  forefinger 
and  thumb  of  the  left  hand. 

Recovery  from  the  Anesthetic. 

From  the  moment  of  the  removal  of  the  face- 
piece,  the  degree  of  narcosis  lightens,  and  anaes- 
thesia passes  into  analgesia,  with  excitement.  The 
pulse,  which  has  been  increased  in  rapidity  and 
tension,  returns  to  its  almost  normal  rhythm  with 
the  first  good  inspiration,  lips  and  skin  regain  their 
normal  hue,  stertor  and  jactitation  disappear,  and 
the  respirations  become  quick  and  shallow  or 
panting. 

The  conjunctivae  lose  their  congested  appear- 
ance and  regain  their  tactile  reflex.  The  patient 
feels  somewhat  dazed,  as  when  awaking  from  a 
de&p  sleep,  but  rapidly  regains  complete  conscious- 
ness, and  complains  of  no  ill-effects. 

As  soon  as  the  extraction  is  complete,  the  head 
and  shoulders  of  the  patient  should  be  drawn 
well  forward,  and  so  blood  prevented  from  getting 
into  the  larynx  and  causing  cough  and  irritation. 
If  the  patient  is  somewhat  slow  in  coming  round, 
provided  colour  and  breathing  are  good,  no 
\dgorous  efforts  should  be  made  to  awake  him, 


NITROUS  OXIDE  67 

and  if  a  prop  has  been  inserted  into  the  mouth, 
it  should  be  left  alone  until  the  patient  is  quite 
conscious,  otherwise  the  forcible  removal  of  it  will 
give  him  a  strong  impression,  most  difficult  to 
eliminate,  that  it  was  the  removal  of  the  tooth 
that  he  felt. 

When  the  mouth  has  been  thoroughly  washed 
out  and  the  haemorrhage  has  stopped,  the  patient 
may  be  allowed  to  sit  back  in  the  chair  a  few 
minutes  before  rising,  as  the  power  of  locomotion 
is  at  first  somewhat  impaired.  He  or  she  may 
then  be  allowed  to  go  to  another  room  for  a 
fiurther  ten  minutes'  rest,  or  at  once  to  a  cab, 
without  any  fear  of  ill-effect. 

Time  taken  to  induce  Anesthesia — 
Duration  of  Anesthesia. 

There  seems  to  be  a  considerable  discrepancy  of 
opinion  on  these  points.  Sir  Frederick  Hewitt 
found  the  average  time  occupied  in  producing  full 
anaesthesia  is  55-9  seconds  when  deaHng  with  a 
fairly  robust,  fuUy-developed  adult.  Silk  gives  it 
as  67-5  seconds,  and  the  committee  of  the  Odonto- 
logical  Society  73  seconds.  Hewitt  found  the 
usual  available  anaesthesia  to  be  30-3  seconds, 
while  the  Odontological  Society  found  it  to  average 
247  seconds  only. 

Children  and  feeble   anaemic  subjects  become 


68    AN.^STHESIA  IN  DENTAL  SURGERY 

rapidly  cyanosed  and  stertorous  with  nitrous 
oxide  often  in  about  20  seconds,  but  the  length  of 
the  anaesthesia  is  usually  correspondingly  short. 

It  is,  of  course,  very  difficult  to  decide  when  the 
true  anaesthesia  terminates.  The  period  of  anaes- 
thesia, however,  depends  to  a  considerable  extent 
on  the  duration  of  the  inhalation,  a  long  inhalation 
usually  affording  a  long  anaesthesia,  and  vice  versa. 

Further,  the  available  anaesthesia  may  be  pro- 
longed for  some  seconds  by  allowing  a  breath  of 
air  at  every  fifth  respiration  during  the  induction 
of  anaesthesia.  This  fact  was  pointed  out  by 
the  late  G.  Rowell;  he  usually  commenced  allow- 
ing air  after  the  patient  had  had  about  fifteen 
breaths  of  pure  gas. 

After-Effects  of  Nitrous  Oxide. 

The  after-effects  of  nitrous  oxide  are  usually 
exceedingly  slight  and  transient;  indeed,  there  is 
no  known  anaesthetic  which  produces  less  consti- 
tutional disturbance. 

Slight  headache  and  vertigo,  accompanied  by 
a  feeling  of  lassitude  and  depression,  are  occasion- 
ally seen.  If  at  all  marked,  some  impurity  in  the 
gas  may  be  suspected,  or  the  administration  may 
have  been  faultily  conducted,  and  too  much 
CO2  inhaled  along  with  the  nitrous  oxide  from 
re  breathing;  or  some  blood  may  have  been 
swallowed. 


NITROUS  OXIDE  69 

If  the  patient  has  had  a  meal  within  the  last 
two  hours,  these  symptoms  are  more  prone  to 
occur,  and  may  be  accompanied  by  nausea  and 
even  active  vomiting.  Accordingly,  it  is  well 
before  administering  to  inquire  when  the  last  meal 
was  taken.  Pallor  and  faintness  are  due  usually 
to  stomachic  disturbance  and  threatened  vomiting 
rather  than  to  any  direct  circulatory  disturbance. 

Two  administrations  at  a  sitting  can  rarely  be 
carried  out  without  causing  a  good  deal  of  after- 
discomfort  and  headache,  and  should  therefore 
not  be  undertaken  unless  the  patient  lives  at  a 
distance  and  it  is  especially  desirable  to  complete 
the  extraction. 

The  author  has  on  several  occasions  seen  a  sort 
of  cataleptic  condition  follow  a  gas  administration 

Continuous  Administration  of  Nitrous  Oxide. 

During  the  last  ten  or  fifteen  years  many 
attempts  have  been  made  to  administer  nitrous 
oxide  in  a  more  or  less  continuous  manner,  so  as 
to  produce  and  maintain  an  anaesthesia  suitable 
for  prolonged  dental  extraction,  and  even  for 
surgical  operations. 

Several  of  the  last  named,  of  a  duration  of  an 
hour  or  more,  have  actually  been  done  with 
nitrous  oxide  anaesthesia  kept  up  by  intermittent 
administration  of  the  gas  by  the  ordinary  appa- 
ratus.    It  will  be  obvious  to  those  acquainted 


70    AN.^STHESIA  IN  DENTAL  SURGERY 

with  the  ordinary  phenomena  of  nitrous  oxide 
anaesthesia,  however,  and  the  quietness  of  breath- 
ing and  muscular  fiaccidity  essential  to  the  per- 
formance of  the  majority  of  the  operations  of 
surgery,  that  the  gas  is  by  no  means  adapted  for 
such  use.  On  the  other  hand,  for  dental  work  it 
always  has  been,  and  probably  always  will  be, 
the  most  popular  and  best-adapted  anaesthetic. 

Some  of  the  methods  employed  to  obtain  a  pro- 
longed anaesthesia  only  require  a  very  brief  notice. 
Coxon  used  a  metal  tube  to  convey  the  gas 
into  the  mouth,  and,  having  produced  anaesthesia 
in  this  way,  he  maintained  it  during  the  extrac- 
tion by  keeping  up  a  continuous  stream  of  gas. 

Harvey  Hilliard  first  induced  anaesthesia  by 
the  ordinary  face-piece,  and  then  kept  up  the 
supply  of  gas  through  a  nasal  tube.  This  latter 
the  author  considers  distinctly  objectionable,  for 
it  is  apt  to  cause  considerable  epistaxis.  Further, 
if  there  be  any  adenoid  growths  or  nasal  obstruc- 
tion, it  cannot  be  used. 

Coleman  in  1899  brought  out  yet  another 
apparatus,  which  consisted  of  a  nose-piece  at- 
tached to  the  gas-bag  by  a  tube,  and  when  in  use 
fixed  by  a  kind  of  clamp  arrangement  to  the 
patient's  head.  Bearing  in  mind  the  varieties  of 
fashions  which  ladies  affect  in  wearing  their  hair, 
the  difficulty  of  making  any  one  fixative  clamp 
generally  adaptable  at  once  suggests  itself. 


NITROUS  OXIDE  71 

This  apparatus,  however,  has  been  the  basis  on 
which  recent  improvements  by  H.  J.  Paterson 
and  others  have  produced  a  thoroughly  reliable 
and  useful  means  of  keeping  up  continuous  gas 
anaesthesia.     For  supplying  the  gas  Paterson  uses 
the    ordinary  two-bottle    gas-stand  with   nozzle 
attachment.     To  this  is  adapted  a  J-inch  rubber 
tube,  which  enters  a  small  2-gaUon  rubber  bag 
to  which  is  fixed  a  two-way  stop-cock.    From  the 
stop-cock  pass  two  narrow,  very  flexible  rubber 
tubes,  which  pass  to  supply  a  metal  nose-piece 
fitted  with  rubber  air-pad  to  admit  of  very  accu- 
rate adaptation  to  the  patient's  nose  and  face. 
Having  filled  the  bag  about  two- thirds  fuU  of  gas, 
a  mouth-prop  is  inserted,  the  nose-piece  carefully 
adjusted,  and  the  stop-cock  turned  on. — A  stream 
of  gas  now  passes  into  the  nasal  passages  during 
each    inhalation.     The    patient    thus     breathes 
nitrous  oxide  through  the  nose  and  a  variable 
quantity  of  air  through  the  mouth.     If,  however, 
anaesthesia  is  slow  in  being  established,  a  celluloid 
mouthpiece  is  provided,  with  an  expiratory  valve 
only,  and  this  is  carefully  adapted  to  the  mouth 
to  prevent  any  air  entering,  while  still  allowdng  the 
patient  to  expire.     In  75  per  cent,  of  cases  anaes- 
thesia may  be  completely  established  in  forty  to 
fifty  seconds  without  any  use  of  the  mouthpiece. 
If  this  is  used,  however,  less  time  will  be  needed. 
The  patient  becomes  only  slightly  dusky,  and  any 


72    ANAESTHESIA  IN  DENTAL  SURGERY 

stertor  or  cyanosis  is  readily  removed  by  stopping 
the  supply  of  gas,  and  turning  the  tap  of  the  two- 
way  stop-cock  so  as  to  lie  horizontally.  In  good 
types  of  patients  who  are  not  nervous  or  alcoholic, 
it  is  quite  possible  to  keep  up  a  safe  anaesthesia 
almost  indefinitely — ^at  any  rate,  for  ten  to  fifteen 
minutes — long  enough  for  a  moderately  dexterous 
operator  to  '  clear  a  mouth.' 

It  is  often  necessary  to  keep  a  good  deal  of 
pressure  on  the  gas-supply,  with  the  bag  dis- 
tended, to  keep  the  patient  well  anaesthetized. 
For  ten  minutes'  anaesthesia  30  to  40  gallons  of 
gas  will  be  necessary. 

On  recovery  from  the  anaesthesia  patients  are 
usually  very  fresh  indeed,  any  disagreeable  after- 
effects being  usually  due  to  swallowed  blood. 
There  is  a  marked  contrast  in  the  condition  of  the 
patient  after  continuous  gas  anaesthesia  and  gas 
and  ethyl  chloride,  or  ethyl  chloride  alone. 

Paterson's  apparatus  has  the  disadvantage  of 
having  only  one  size  of  nose-piece,  which  is  made 
of  fairly  thick  white  metal,  and  is  thus  by  no 
means  readily  adaptable  to  the  large  variety  of 
noses  which  we  find  in  the  human  species. 

Nash,  of  Ayr,  recognizing  this  drawback,  has 
made  the  nose  -  piece  in  several  sizes  of  thin, 
pliable  copper  plate,  and  has  effected  a  great 
improvement.  He  has  also  supplied  the  nose- 
piece  with  an  expiratory  valve,  which  modifies  the 


NITROUS  OXIDE 


73 


FIG,    12. PATERSON's   APPARATUS 


74    AN.ESTHESIA  IN  DENTAL  SURGERY 

technique  in  this  respect,  that  instead  of  telling 
the  patient  to  '  Breathe  in  through  the  nose  and 
out  through  the  mouth,'  one  simply  directs  him 
to  '  Breathe  to  and  fro  through  the  nose.' 


Advantages  of  the  Nasal  Method. 

It  is  a  quick  and  safe  method  of  obtaining  one 
to  ten  minutes'  anaesthesia,  but  especially  useful 
where  only  two  or  three  minutes'  anaesthesia  are 
wanted,  for  the  removal  of  four  temporary  molars, 
two  or  three  roots,  or  any  procedure  requiring 
rather  more  than  the  time  obtained  when  gas  is 
given  by  the  ordinary  way.  The  patients  are 
able  to  leave  the  dentist's  room  almost  immedi- 
ately, nausea  and  vomiting  being  extremely  rare. 
In  this  respect  the  method  compares  most  favour- 
ably with  ethyl  chloride  or  '  gas  and  ethyl  chlor- 
ide,' and  there  is  no  unpleasant  smell  or  taste  to 
complain  of. 

Disadvantages. 

Unless  the  dentist  has  a  capable  assistant  who 
can  either  act  as  anaesthetist  or  operator,  the 
apparatus  cannot  be  used  without  outside  assist- 
ance. Further,  a  third  person  is  almost  needed  to 
sponge  and  change  the  mouth- props  if  necessary, 
or  insert  a  Mason's  gag.  Considerable  skill  and 
practice  are  needed  to  use  the  apparatus  efficiently, 


NITROUS  OXIDE  75 

while  the  risk  of  overdose  from  nitrous  oxide,  if 
air  be  not  duly  suppKed  from  time  to  time,  is  of 
course  increased. 

As  Bellamy  Gardner  points  out,  the  great 
advantage  of  the  nasal  apparatus  for  systematic 
induction  of  N2O  anaesthesia  is  that  we  never  need 
charge  the  patient  up  with  the  gas.  We  may 
divide  fuU  NgO  anaesthesia  when  there  is  stertor, 
lividity,  and  jactitation  into,  say,  ten  degrees. 
If  w^e  are  giving  the  gas  nasally  we  need  only  reach, 
say,  the  fifth  degree,  when  the  patient  is  ready, 
and  aU  we  have  to  do  is  to  keep  him  anaesthetized 
and  maintain  a  good  colour. 

After  being  in  use  for  some  time  the  elasticity 
of  the  bag  decreases,  and  it  is  often  necessary  to 
get  a  new  bag  or  to  maintain  the  pressure  by  keep- 
ing the  bag  between  the  dental  chair  and  the 
anaesthetist's  knee,  but  this  is  readily  done. 

Lastly,  the  cost  of  the  often  considerable 
amount  of  gas  used  is  too  great  to  admit  of  this 
method  being  much  used  except  in  good-class 
private  practice. 

When  young  children  from  seven  to  twelve  are 
kept  under  gas  for  any  time  screaming  and  crying 
out  are  very  common.  It  is  a  great  drawback  if 
friends  are  present,  as  it  is  difficult  to  persuade 
them  nothing  has  been  felt,  although  the  child 
may  regain  consciousness  with  a  smile. 


Details  of  ioo  Cases  of  An.esthesia  pro- 
duced BY  Continuous  Administration  of 
Nitrous  Oxide. 

Average  anaesthesia,  2*84  minutes. 
Average  time  for  induction,  35  to  40  seconds. 


Duration 

i 

No.  ;  Sex. 

1 

Age. 

of  Anaes- 
thesia. 

Extractions. 

Remarks. 

1 

Minutes. 

I      F. 

14 

5 

12 

Noisy.       Thirty    gal- 

lons gas  used. 

2 

F. 

54 

I 

7 

Patient  very  feeble. 

3      F. 

26 

4-5 

5  stumps 

Hypnotic  condition 
afterwards. 

4      M. 

19 

3 

3  stumps 

5      F. 

14 

I 

4  temp, 
molars 

6      F. 

17 

5 

17  teeth 

Very  fresh  afterwards. 

7 

F. 

35 

2-5 

6     ,, 

Opisthotonos. 

8 

F. 

30 

5 

16     ,, 

Excellent  colour. 

9 

M. 

28 

4 

4  stumps 

Powerful  man. 

10 

F. 

28 

4 

2 

Very  good  colour. 

II 

F. 

23 

1-5 

8  teeth 

12 

F. 

10 

3 

4  temp, 
molars 

Very  refractory  child ; 
started  with  ordin- 
ary face-piece,  and 
changed  to  Pater- 
son  after. 

13 

M. 

22 

3-5 

3  stumps 

Some  cyanosis. 

14 

M. 

9 

3 

3       .. 

15 

F. 

35 

2 

2 

JMitral  stenosis ;  feeble 
patient. 

16 

F. 

24 

2 

12  teeth 

Screaming. 

17 

M. 

20 

1-5 

I  very  bad 
stump 

18 

M. 

9 

3 

2  stumps 

19 

F. 

35 

3-25 

4      .. 

20 

M. 

12 

4 

4  temp, 
molars 

21 

F. 

32 

3 

16  teeth 

22 

F. 

27 

2 

2  stumps 

23 

F. 

12 

2 

I  very  bad 
stump 

24 

M. 

45 

2 

3  teeth 

Alcoholic ;  violent 
struggling  and  pho- 
nation.  Broke  arm 
off  chair. 

25 

F. 

20 

2 

3    .. 

26 

F. 

30 

2 

I  root 

76 


Details  of  ioo  Cases  of  Anesthesia  (contd.). 


Duration 

, 

No.     Sex. 

Age.; 

! 

of  Anaes- 
thesia. 

Extractions.      i 

1 

Remarks. 

Minutes, 

27     M. 

23 

3          1 

I  very  bad 
root 

28      F. 

25 : 

I 

I  very  bad 
root 

29     F. 

32 

0-75 

I  tooth 

Seventh     month     of 

1 

pregnancy ;       very 

1 

1 

' 

delicate.     No    cya- 

j 

nosis  or  jactitation. 

30 

F. 

45 

3 

8  teeth 

31 

F.   i 

34 ' 

I 

2  "  ,, 

32 

F. 

30  : 

5 

13     .. 

33 

F. 

30 

4*5 

12  stumps 

34 

F. 

27 

I 

I  stump 

35 

M. 

44  1 

1-5 

18  teeth 

36 

F. 

19  i 

3 

8     .,            ' 

37 

F. 

35  ■ 

3*5 

12     ,, 

38 

M. 

44 

2-5 

10     ,, 

39 

F.   ; 

26 

3 

13     " 

40 

M. 

62  i 

3-5    ; 

1 

5     >. 

Very  acute  gum-boil 
upper  lip.  Nose- 
piece  changed  to 
large  face-piece. 

41 

M. 

10 

2-5 

4  temp, 
molars        j 

42 

M. 

18 

3*5 

10  teeth 

43 

F. 

26 

3 

10     ,, 

44 

F. 

35 

2          , 

4     .. 

45 

F. 

32 

I 

2     ,, 

Nervous.  Opistho- 
tonos. Shaky  after- 
wards. 

46 

F. 

32 

1*5 

5  roots 

47 

>  M. 

1 

1 

48 

2 

2  stifi 
molars 

Opisthotonos  and 
stertor. 

48 

F. 

30 

5 

19 

Phonation ;  very  fresh 
after. 

49 

F. 

32 

3 

3 

Noisy.   Opisthotonos. 

50 

M. 

54 

2 

12 

Very  robust  patient. 

51 

M. 

18 

8 

16 

52 

F. 

28 

10 

18 

53      F. 

19 

4*5 

12 

Excellent  colour. 

54  ;  M. 

1 

12 

4 

5 

Two  administrations; 
i       vomited;      three 
hours  since  food. 

55      F. 

15 

2*5 

4  stumps 

Very  good  colour. 

56  i  F. 

24 

5 

15      .. 

57  1  F. 

26 

2*5 

4      .. 

58  •  ^■ 

18 

3*5 

8  teeth 

59  j  F. 

29 

i      5*5 

29     ., 

Very      fresh      after ; 
!       walked  home. 

77 


Details  of  ioo  Cases  of  Anesthesia  (contd.). 


Duration    1 

No.     Sex. 

Age. 

ofAnaes-    i 
thesia. 

Extractions.      1 

1 

Remarks. 

Minutes.    1 

60      F. 

34 

1-5 

1 2  teeth 

61 

M. 

23 

7               : 

29     .. 

62  ; 

F. 

27 

6-5 

25     .. 

63 

F. 

21 

2        ! 

4  roots 

64 

M. 

17 

2        1 

8     ,, 

65    ' 

F. 

20 

1-75     1 

17  teeth 

Patient  very  pleased. 

66  i 

F. 

13 

1-5       1 

4     .. 

Temporary  molars. 

67  1 

F. 

30 

2 

8 

68  i 

1 

F. 

33 

3 

4 

One  a  very  bad 
stump. 

69 

F. 

29 

3 

7 

70 

M. 

28 

2-5       ! 

9 

71 

F. 

23 

2 

3  roots          ' 

Deaf-mute.     , 

72 

F. 

38 

2-5       1 

5     .. 

J 

73 

F. 

28 

1-75 

3 

74 

F. 

50 

I 

I  root 

75 

F. 

13 

1*3 

4 

76  . 

M.  1 

21 

2 

4 

77 

F. 

35 

3 

(Antrum 
case) 

Patient  very  cya- 
nosed.  High  colour. 

78 

F. 

13 

1-5       i 

4 

Temporary  molars. 

79 

F. 

38 

3          ! 

I 

Very  bad  stump. 

80 

M. 

12 

1-25 

4 

Temporary  molars. 
Loud  phonation; 
awoke  smiling. 

81 

F. 

22 

5 

9  teeth 

Three  pulps  were  also 
drilled  out. 

82 

F. 

27 

1-5 

2  roots 

83 

M. 

35 

3 

I  root 

A  very  stiff  root. 

84 

M. 

20 

3-5 

9  roots 

85 

F. 

30 

1-25 

3      .. 

86 

M. 

35 

I 

5  teeth 

Marked  opisthotonos; 
stopped  adminis- 
tration. 

87 

1  M. 

38 

9 

12     ,, 

Forty  gallons  NgO 
used. 

88 

i  F. 

28 

3 

10 

Opisthotonos. 

•89 

1  M. 

30 

1-5 

3  roots 

90 

'  M. 

24 

1-5 

I  root 

91 

.  F. 

66 

1-25 

4  teeth 

92 

i  F. 

35 

I 

I  root 

93 

F. 

45 

1-5 

5  teeth 

94 

F. 

40 

I 

4     - 

95 

F. 

28 

8 

18     ,, 

96 

F. 

30 

3*5 

5  roots 

97 

M. 

28 

4 

'     7  teeth 

Noisy. 

98  !  F. 

1  48 

2-5 

8     .. 

99  1  F. 

39 

2 

3     w 

100  1  M. 

24 

2 

3     .. 

Opisthotonos. 

78 


CHAPTER  IV 

ETHYL  CHLORIDE  (C2H5CI) 

Ethyl  chloride,  first  employed  by  Heyfelder,  is  a 
colourless,  highly  volatile  liquid  of  aromatic  odour 
and  sweetish  taste  and  neutral  reaction.  It 
volatilizes  at  all  ordinary  temperatiires  without 
leaving  any  residue,  but  if  at  all  decomposed  gives 
off  a  slightly  garlicky  odour  from  the  skin  when 
evaporated  on  the  palm  of  the  hand.  It  has  a 
density  of  0-92  at  0°  C,  and  the  density  of  the 
vapour,  taking  air  at  unity,  is  2-3.  It  boils  at 
12-5°  C. 

It  is  very  readily  soluble  in  alcohol,  but  sparingly 
so  in  ether.  The  drug  is  very  combustible,  burn- 
ing with  a  green  flame  and  setting  free  hydro- 
chloric acid.  It  is  manufactured  by  subjecting 
a  boiling  solution  of  chloride  of  zinc  (in  alcohol) 
to  the  action  of  hydrochloric  acid.  When  put  up 
in  cyhnders  holding  from  50  to  60  c.c,  it  shows 
no  tendency  to  decompose  or  undergo  chemical 
change  even  when  exposed  to  hght.  Its  purchase 
in  larger  bulk  than  this  is  not  to  be  advised,  except 
to  those  who  are  skilled  chemists  and  accustomed 

79 


8o    ANAESTHESIA  IN  DENTAL  SURGERY 

to  handling  very  volatile  substances.  Ethyl 
chloride  has  a  solvent  action  on  various  substances, 
but  no  appreciative  action  on  rubber  sheeting, 
any  more  than  sulphuric  ether.  It  will,  however, 
rapidly  destroy  vulcanite  stop-cocks. 

In  spite  of  its  extreme  volatility,  if  a  few  c.c. 
be  decanted  into  a  small  test-tube  of  thick  glass 
no  considerable  amount  of  the  drug  will  be  lost, 
even  if  the  tube  be  exposed  for  from  five  to  ten 
minutes  in  a  room  at  70°  F.  But  the  tendency  to 
ebullition  is  very  marked  if  a  small  particle  of  glass 
or  metal  be  dropped  into  the  tube. 


Apparatus  for  administering  Ethyl  Chloride. 

WTiile  various  methods  have  been  suggested 
for  administering  the  drug,  and  patients  have  been 
and  can  be  anaesthetized  by  open  methods,  one 
has  no  hesitation  in  saying  that  the  only  satis- 
factory method  is  the  closed  method  with  some 
type  of  bag  inhaler.  It  should  be  simple  in 
design  and  have  a  wide  bore.  Merely  to  render 
a  patient  unconscious  or  semi-anaesthetized  as  a 
preliminary  to  ether  or  chloroform  anaesthesia  the 
drug  may  be  given  on  a  handkerchief  folded  into 
the  form  of  a  cone,  or  a  piece  of  lint  with  jaconet 
over  it.  Indeed,  when  dealing  with  nervous  and 
excitable  people  or  children,  this  may  be  even 


ETHYL  CHLORIDE  8i 

advantageous,  but  where  a  full  anaesthesia  is 
required  it  is  useless. 

In  detective  stories  we  read  of  the  magical  way 
in  which  a  few  drops  of  chloroform  on  a  handker- 
chief serve  to  render  the  hero  or  heroine  uncon- 
scious while  the  viUain  of  the  piece  works  his 
nefarious  will.  Everyone  who  has  the  slightest 
acquaintance  with  chloroform  and  its  action 
knows  this  to  be  absurd,  but  with  a  lavish  use  of 
ethyl  chloride  something  of  the  kind  might  be 
effected. 

As  regards  closed  inhalers,  the  essential  parts 
are — 

(i)  A  good  face-piece  with  a  pneumatic  pad. 

(2)  A  rubber  bag  of  i-gallon  capacity. 

(3)  A  metal  angle  junction  tube  with  an  aper- 
ture at  one  aspect,  or  another  through  which  the 
ethyl  chloride  may  be  introduced.  Or  alter- 
natively, as  in  Guy's  apparatus,  the  mount  may  be 
fitted  with  a  two-way  stop-cock. 

In  the  interests  of  accurate  dosage,  it  is  a  good 
plan  to  have  a  smaU  piece  of  rubber  tube  extended 
from  the  bottom  of  the  bag,  to  which  is  then 
attached  a  glass  test-tube  capable  of  holding  about 
5  c.c.  of  ethyl  chloride,  into  which  the  drug  is 
carefully  measured.  This  test-tube  should  be 
marked  at  3  c.c.  and  5  c.c.  By  means  of  it  an 
absolutely  definite  quantity  of  ethyl  chloride  can 

6 


82    AN.^STHESIA  IN  DENTAL  SURGERY 

be  administered  as  the  initial  dose,  and  if  there  be 
any  need  to  use  more  (in  the  large  majority  of 
cases  there  is  no  need),  it  may  be  added  by  means 
of   the    aperture    in    the    angle-tube.     In   Guy's 
inhaler,  which  is  shown  on  p.  152,  there  is  some 
little  difference  in  actual  structure,  although  the 
principle  is  essentially  the  same.     The  apparatus 
is  shghtly  more  complicated.     He  uses  a  >Barth 
three-way  tap,  which  carries  a  feed-tube  mounted 
on  a  ball-and-socket  joint.     Through  this  tube 
gas  or  ethyl  chloride  is  introduced  into  the  bag. 
Fig.  18  shows  the  arrangement.     A  hole  is  made 
halfway  up  the   upper  part  of  the  bag-mount; 
the  feed-tube  mounted  in  its  ball-and-socket  joint 
is  continuous  with  the  hole.     In  the  perpendicular 
arm  of  the  three-way  tap  a  corresponding  hole  is 
made ;  a  pointer  on  the  bag-mount  and  an  arrow- 
head on  the  perpendicular  arm  of  the  tap  serve  to 
show  when  the  two  holes  are  in  apposition.     As 
an  additional  convenience,  another  hole  is  made 
exactly  opposite,  so  that  gas  or  ethyl  chloride  can 
be  introduced  on  either  side. 

Guy  has  a  special  glass  measure  with  a  base 
on  which  it  can  readily  stand.  To  use  this 
inhaler  for  ethyl  chloride  alone,  the  drug  is 
sprayed  into  the  measure,  which  is  then  attached 
to  the  tube;  the  tube  should  be  adjusted  in  its 
most  dependent  position.     The  pointer  of  the  tap 


ETHYL  CHLORIDE  83 

is  put  at  'No  valves,'  the  face-piece  being  adjusted 
to  the  patient's  face;  the  feed-tube  is  raised,  and 
the  ethyl  chloride  slowly  tilted  into  the  bag.  This 
apparatus  can  be  equally  well  adapted  for  the 
administration  of  gas,  or  gas  and  ether,  etc. 

It  will  be  seen,  then,  that  to  make  a  thoroughly 
satisfactory  inhaler  for  ethyl  chloride  we  have  to 
only  sHghtly  modify  the  parts  of  an  ordinary 
Clover's  inhaler,  having  put  the  ether  chamber 
aside.  The  modifications  are  such  that  any  in- 
strument-maker can  carry  them  out  at  a  trifling 
cost;  and  this  is  a  point  of  some  importance,  as 
many  dental  and  medical  practitioners  alreadv 
possess  a  Clover's  inhaler.  No  part  of  the  inhaler 
should  be  made  of  vulcanite,  owing  to  the  tendency 
of  this  to  perish  under  the  action  of  ethyl  chloride. 
Either  red  or  black  rubber  will  do  for  the  bag  and 
face -piece,  but  on  the  whole  the  red  rubber  lasts 
longer. 

McCardie  and  Harvey  Hilliard  have  advocated 
the  use  of  an  Ormsby  inhaler  for  ethyl  chloride, 
and  the  writers  agree  that  it  answers  well,  although 
he  prefers  to  us?  one  of  the  inhalers  already  de- 
scribed as  being  better  adapted  for  accurate  dosage. 
The  construction  of  special  inhalers  for  the  adminis- 
tration of  ethyl  chloride  is  to  be  deprecated,  for 
there  is  no  necessity  for  them,  and  they  lead  to 
confusion  and  bad  results  rather  than  otherwise- 


84    ANESTHESIA  IN  DENTAL  SURGERY 

There  have  been  an  endless  number  of  them  placed 
on  the  market  from  time  to  time,  especially  v.  hen 
the  drug  first  came  into  vogue,  but  their  multi- 
plication is  more  calculated  to  further  the  com- 
mercial interests  of  the  instrument-maker  than 
to  be  of  any  service  to  the  profession  at  large. 

We  consider  the  employment  of  lint  or  small 
sponges  in  closed  inhalers  not  only  unnecessary, 
but  actually  disadvantageous.  Lint  and  sponge 
almost  invariably  freeze,  and  render  the  induc- 
tion of  anaesthesia  unduly  slow.  Ethyl  chloride 
sprayed  into  the  bag  in  quantities  of  5  to  8  c.c. 
rapidly  vaporizes,  and  does  no  harm  to  the  rubber 
of  the  bag  or  face-piece. 

Rebreathing. 
A  word  may  be  said  here  about  rebreathing. 
Wherever  a  closed  form  of  inhaler  is  used,  be  it 
a  Clover  or  gas  or  gas  and  oxygen  of  one  type  or 
another,  a  certain  amount  of  rebreathing  at  times 
is  allowed  and  may  be  desirable.  iEsthetically 
there  are  certainly  objections  to  reinhaling  one's 
own  exhalations,  but  one  has  to  remember,  as 
Flagg  points  out,  that  our  ordinary  respirations 
under  even  modern  housing  conditions  involve 
a  good  deal  of  rebreathing.  Flagg  states  that  with 
the  total  vital  capacity  of  the  lungs  put  at  3,700 
CO.,  only  about  500  c.c.  is,  as  a  rule,  actually  fresh 


ETHYL  CHLORIDE  85 

air  with  ordinary  quiet  respiration.  Under  such 
circumstances  we  rebreathemore  than  six-sevenths 
of  the  air  which  we  use  for  respiratory  purposes. 
Re  breathing  from  a  bag  is,  therefore,  relative 
rather  than  absolute  difference.  Disagreeable 
effects  from  COg  are  rather  due  to  an  absence  of 
oxygen — anoxaemia — than  to  the  COg.  Five  per 
cent,  to  six  per  cent,  of  COg  temporarily  with 
adequate  oxygen  produces  little,  if  any,  harmful 
effect  in  all  probability. 

It  is  not  generally  understood  that  cyanosis  has 
nothing  to  do  with  the  amount  of  COg  in  the  blood. 
The  gas  usually  exists  in  the  blood  in  simple  solu- 
tion and  in  chemical  combination  with  alkalis 
present.  The  colour  of  blood  is  dependent  on  the 
corpuscles  and  the  amount  of  Hb  contained  in 
individual  cells.  The  controlling  element  is  really 
the  haemoglobin,  and  when  it  is  exposed  to  oxygen, 
oxyhaemoglobin  is  formed,  giving  blood  its  charac- 
teristic hue.  Duskiness  is  due  to  reduction  of 
the  oxyhaemoglobin,  and  further  reduction  will 
cause  lividity.  Flagg  holds  that  rebreathing  may 
even  be  beneficial  in  a  long  anaesthesia,  in  that  the 
presence  of  COg  in  the  blood-corpuscles  increases 
the  frequency  with  which  the  Hb  parts  with  its 
oxygen  and  promotes  oxygenation  of  the  vital 
tissues. 

Probably  carbon   monoxide    (CO)   is   confused 


86    ANAESTHESIA  IN  DENTAL  SURGERY 

with  COg  by  some  people,  and,  as  is  well  known, 
this  gas  forms  a  very  close  combination  with  Hb, 
excluding  oxygen  and  causing  early  death  from 
anoxaemia. 

Preparation  of  the  Patient. 

The  patient  should  have  abstained  from  food 
for  a  period  of  not  less  than  two  hours  prior  to  the 
administration  of  ethyl  chloride.  If  the  stomach, 
rectum,  and  bladder  be  not  empty  beforehand,  they 
are  very  likely  to  empty  themselves  reflexly 
during  or  after  the  anaesthesia,  and  this  is  par- 
ticularly so  in  children. 

If  there  be  any  dentures  present  in  the  mouth 
they  should  be  removed,  and  anything  tight  about 
the  neck  or  corsets  should  be  loosened  or  taken  off. 
It  is  a  wise  precaution  in  all  cases  to  have  heart 
and  lungs  examined  by  the  patient's  ordinary 
medical  attendant,  not  so  much  from  the  liability 
of  disease  being  present  such  as  would  contra- 
indicate  the  use  of  ethyl  chloride  and  indicate 
another  anaesthetic,  but  as  a  means  of  establishing 
the  patient's  confidence  and  being  prepared  for 
any  eventuality. 

Posture  of  the  Patient. 

There  is  no  contra-indication  whatever  to  the 
sitting-up  posture,  unless  the  operator  prefer  the 


ETHYL  CHLORIDE  87 

lying-down  position;  this  position  is  often  more 
suitable  for  young  children,  as  they  are  apt  to 
slip  down  in  the  chair  and  collapse  in  a  heap,  to 
the  embarrassment  of  all  concerned.  When  the 
sitting-up  position  is  utilized,  however,  the  head 
must  not  be  put  too  far  back,  for  if  this  be  done 
the  trachea  becomes  pressed  upon  by  the  neck 
muscles,  and  the  respiration  gets  embarrassed. 
The  coronal  plane  of  the  he^ad  should  be  in  the 
same  vertical  as  is  the  spinal  column. 

The  Administration. 

The  ethyl  chloride  having  been  accurately 
measured,  the  face-piece  is  carefully  adjusted  and 
the  patient  told  to  breathe  away  quietly  to  and 
from  the  bag.  Whether  the  ethyl  chloride  be 
introduced  into  the  bag  from  a  graduated  test- 
tube  or  directly,  it  is  well  to  do  this  gradually, 
as  otherwise  the  vapour  may  be  too  pungent  and 
cause  the  patient  to  hold  his  breath.  After  about 
six  to  eight  full  breaths  the  respiration  becomes 
deeper,  and  the  pupils  contract  somewhat,  but 
they  then  almost  immediately  begin  to  dilate  and 
lose  their  reaction  to  light.  The  pupil  is  dilated 
in  40  per  cent,  of  cases,  contracted  in  8  per 
cent.,  and  practically  unchanged  in  52  per  cent. 
(Reboul). 

The  eyes  become  fixed  in  one  axis,  and  the  con- 


8S  ANESTHESIA  IX  DENTAL  SURGERY 

junctival  reflex  is  lost.     It  is  important  not  to  push 
the  anaesthetic  after  this  happens,   or  until  the 
cough  reflex  disappears,  as  there  is  considerable 
risk  of  solid  matter  getting  down  the  air-passages. 
The  muscles  become  relaxed,  as  a  rule,  through- 
out the  body,  with  the  exception  of  the  masse ter 
muscle,  which  very  often  goes  into  spasm.     This 
constitutes  one  of  the  drawbacks  to  the  drug,  and 
to  avoid  waste  of  time  in  opening  the  mouth  the 
use  of  a  mouth-prop  inserted  prior  to  the  com- 
mencement of  the  inhalation  is  desirable,  just  as 
in  the  case  of  nitrous  oxide  gas.     The  pulse  is  full 
and  bounding,  and  if  a  sphygmographic  tracing  be 
taken  it  shows  a  clearly- defined  tidal  wave.     The 
patient's  face  is  flushed,  and  sometimes  beads  of 
perspiration  appear  very  soon  on  the  forehead. 
Unconsciousness    supervenes   in   from    i8   to   25 
seconds,  and  on  the  average  a  full  anaesthesia  is 
obtained  in  50-9  seconds,   allowing  an  available 
period  for  operating  of  71-3  seconds  (McCardie). 
The  wTiter  has  found,  however,  that  where  a  longer 
period  than  this  is  desired,  it  can  be  obtained 
without  difficulty  by  pushing  the  drug  somewhat, 
although  at  all  times  caution  is  necessary  in  this 
respect. 

As  regards  the  stages  of  anaesthesia,  Malherbe 
and  Laval  described  the  following: 

I.  An  analgesic  stage,  which  commences  after 


ETHYL  CHLORIDE  89 

two  or  three  breaths  of  the  anaesthetic  and  lasts 
thirty  seconds  or  thereabouts. 

2.  An  anaesthetic  stage,  which  lasts  from  two 
to  three  minutes. 

3.  A  second  analgesic  stage,  during  which  the 
patient  may  move  and  talk,  but  feels  nothing. 

Any  trouble  that  the  authors  have  had  with 
ethyl  chloride  has  been  respiratory  in  character. 
Cyanosis  and  spasm  of  the  chest  muscles  comes 
on  in  certain  subjects,  especially  muscular  males, 
with  alarming  rapidity,  but  is  not  serious  if  the 
anaesthetist  keep  his  head. 

If  a  wedge  or  gag  be  not  in  the  mouth,  one  must 
be  inserted  at  once,  and  a  free  air- way  established 
by  means  of  traction  on  the  tongue,  etc.,  and 
artificial  respiration  applied,  which,  with  the 
withdrawal  of  the  anaesthetic,  usually  rapidly 
restores  the  patient's  respiratory  equihbrium  and 
normal  colour. 

After-Effects. 

The  after-effects  vary  considerably  in  different 
subjects.  They  are  also,  of  course,  affected  by 
the  length  of  the  administration. 

Vomiting  is  the  most  common  and  most  un- 
pleasant sequela,  occurring  in  15  to  20  per  cent, 
of  cases,  and  nausea  in  a  greater  percentage. 

As  regards  the  character  of  the  sickness,  it  re- 


90   ANAESTHESIA  IN  DENTAL  SURGERY 

scmbles  that  which  is  seen  after  ether  anaesthesia, 
violent  while  it  lasts  and  of  short  duration.  It  is 
often  over  in  fifteen  minutes,  and  anything  longer 
than  three  to  four  hours  is  quite  exceptional. 
McCardie  records  one  case  of  thirty  hours.  As 
noted  elsewhere,  sickness  and  nausea  are  much  less 
common  when  nitrous  oxide  or  oxygen  are  given 
along  with  the  ethyl  chloride. 

The  writers  find  that  sickness  occurs  more  often 
among  private  patients  than  in  hospital,  but 
Harvey  HiUiard  finds  the  contrary  to  be  the  case. 

A  great  deal  depends  on  the  manner  in  which 
the  patients  have  been  prepared,  and,  in  short, 
whether  they  have  had  a  meal  recently  or  not. 
Patients  who  have  come  from  a  distance  and  who 
are  anaesthetized  late  in  the  day  are  more  com- 
monly upset  than  those  who  are  dealt  with  in  the 
morning  after  a  Hght  meal  taken  early. 

Hysterical  symptoms  are  fairly  common  with 
young  girls,  associated  with  profuse  lachryma- 
tion  on  regaining  consciousness. 

The  drug  has  a  distinct  tendency  to  promote 
erotic  thoughts  and  dreams,  and  even  sensuous 
movements  of  the  patient's  limbs,  etc.,  while  in 
the  semi-anaesthetic  state.  Subsequent  accusa- 
tions by  females  of  indecent  assault  have  been 
recorded.  Marshall  of  Liverpool  mentions  two 
such  cases  and  McCardie  another. 


ETHYL  CHLORIDE  91 

Fainting  and  collapse  are  seen  at  times,  but  are 
usually  associated  with  vomiting,  etc.  Jaundice 
is  uncommon  as  a  late  sequela,  but  some  cases 
have  been  noted  in  Paris.  Albuminuria  is  un- 
known in  healthy  people,  except  after  prolonged 
narcoses  of  half  an  hour  or  more .  Fatty  degenera- 
tion of  the  Hver  and  kidneys  has  been  noticed 
after  repeated  administration. 

General  Conclusions  as  regards  Ethyl 
Chloride  for  General  Anesthesia. 

1.  It  is  rapid  and  pleasant  in  action,  and  a  very 
portable  substance. 

2.  As  regards  period  available  for  operative  pro- 
cedure, it  compares  very  favourably  with  nitrous 
oxide,  always  remembering  it  is  much  less  safe  in 
all  subjects. 

3.  It  causes  Httle  or  no  cyanosis  under  ordinary 
circumstances.  If  this  is  noticeable  it  is  either 
due  to  excessive  rebreathing  or  to  commencing 
respiratory  spasm. 

4.  The  administration  is  very  simple  in  tech- 
nique. 

5.  The  drug  is  safer  as  an  anaesthetic  agent  than 
ether,  ethyl  bromide,  or  chloroform. 

6.  It  can  be  re  administered  at  a  sitting,  thus 
having  an  advantage  over  ethyl  bromide. 


92    ANAESTHESIA  IN  DENTAL  SURGERY 

7.  Although  vomiting  is  fairly  frequent,  it  is 
not  followed  by  any  severe  after-effects. 

8.  It  is  cheaper  than  nitrous  oxide,  and,  of 
course,  infinitely  more  portable  and  convenient 
in  the  country. 

9.  It  is  to  be  preferred  to  nitrous  oxide  in  very 
3^oung  subjects,  in  the  anaemic,  for  alcoholics  in 
whom  NgO  has  very  little  effect,  and  for  those  who 
smoke  to  excess.  For  some  of  these  cases  a  com- 
bination of  nitrous  oxide  with  the  ethyl  chloride 
may  be  desirable. 

10.  The  somewhat  sickly  odour  is  objected  to 
by  a  few  patients,  but  may  be  disguised  by  a 
httle  perfume. 

11.  While  in  certain  subjects  the  degree  of  after- 
sickness  is  a  serious  drawback  (modified  by 
adequate  preparation),  and  the  indiscriminate 
and  haphazard  manner  in  which  ethyl  chloride 
was  administered  all  over  the  country  by  un- 
qualified and  irresponsible  persons  threatened 
at  one  time  to  bring  the  drug  into  disrepute  from 
the  occurrence  of  a  considerable  number  of  fatali- 
ties, we  are  of  the  opinion  that  ethyl  chloride 
administered  skilfully  with  all  due  precautions  is 
a  safe  and  in  many  ways  admirable  anaesthetic. 
For  some  reason  it  hardly  ever  gained  the  appre- 
ciation in  London  which  it  has  acquired  in  the 
provinces  and  abroad,  but  that  it  is  now  largely 


ETHYL  CHLORIDE  93 

used  with  advantage  where  formerly  either  chloro- 
form or  ether  would  have  been  considered  indis- 
pensable there  is  no  doubt.  It  must  be  put  into 
a  quite  different  category,  however,  from  nitrous 
oxide  as  regards  safety. 

It  should  be  avoided  in  old  people  except  for 
very  brief  anaesthesias;  it  should  not  be  given  to 
asthmatics  or  bronchitics  or  to  those  with 
established  kidney  trouble.  There  is  special 
danger  in  advanced  pregnancy,  the  very  obese, 
or  those  with  large  abdominal  tumours,  and  in 
any  condition  involving  constriction  of  the  air- 
passages:  all  for  the  same  reason' — ^viz.,  that 
respiratory  difficulties  are  specially  Hable  to  arise 
here,  and  the  trouble  we  have  with  this  drug  is 
usually  respiratory  rather  than  circulatory. 


CHAPTER    V 

ETHER 

Ether  was  probably  discovered  chemically  by 
Michael  Faraday,  but  Crawford  W.  Long  first 
used  it  as  an  anaesthetic  in  1843.  He  appears  to 
have  not  thought  very  much  about  it,  however, 
as  he  left  it  to  Morton  to  claim  the  credit  some 
three  years  later. 

Ether  is  a  very  volatile,  highly  inflammable 
liquid  devoid  of  colour,  but  with  a  peculiarly 
characteristic  odour  and  hot  taste.  It  contains 
about  8  per  cent,  of  spirit,  and  boils  at  100°  F. 
The  specific  gravity  varies  slightly,  according  to 
the  purity,  the  range  being  720 — 735. 

Crude  methylated  ether  is  unsuitable  for  anaes- 
thetic purposes,  but  good  ether  can  be  prepared 
from  it,  known  as  '  aether  purificatus.'  Ether 
prepared  from  pure  ethylic  alcohol  is  really  un- 
necessarily expensive  when  this  variety  can  be 
obtained. 

For  dental  purposes  the  open  method  of  ether 
need  hardly  be  considered.     In   a  case  of  very 

94 


ETHER  95 

severe  toothache  for  the  time  incurable,  except 
by  extraction,  a  dental  surgeon  might  suggest  the 
inhalation  of  a  few  drops  of  ether  on  a  handkerchief 
as  an  analgesic,  but  it  is  quite  out  of  count  for 
operative  purposes.  The  semi-open  method  is 
almost  as  much  so,  leaving  us  merely  the  closed 
method  to  consider. 

The  Closed  Method. 

The  essential  ingredients  in  the  closed  method 
are  (i)  a  good  face-piece;  (2)  some  closed  chamber 
of  varying  type  for  containing  the  Hquid  ether; 
and  (3)  the  ultimate  bag  (i  gallon)  from  which 
the  patient  inhales  the  mixture  of  ether  and  air 
in  varjdng  percentage. 

Several  inhalers  conform  to  these  requisites. 
Ormsby's,  Clement  Lucas's  (with  a  simple  glass 
chamber  and  contained  sponge),  Bellamy  Gard- 
ner's, Hewitt's,  and  Clover's. 

For  all  practical  purposes  we  may  eliminate 
the  first  three,  as  for  one  occasion  on  which  they 
are  used  Clover's  is  used  fifty  times  and  Hewitt's 
five  times  at  the  very  least. 

Clover's  inhaler  was  brought  out  in  1877,  and 
has  been  facile  princeps  ever  since.  While  the 
wide  bore  in  that  devised  by  Hewitt  has  an 
advantage  in  allowing  of  freer  breathing  in  some 
ways,   taking  it   all  round,   Clover's   is    the  best 


96    ANiESTHESIA  IN  DENTAL  SURGERY 

apparatus  for  the  closed  administration  of  ether  ever 
devised,  and  the  principle  adopted  in  Hewitt's  is, 
of  course,  the  same.  It  is  essential  to  procure 
one  from  a  reliable  high-class  instrument-maker 
and  not  a  cheap  type,  the  bore  of  which  is  usually 
narrow  and  the  instrument  sometimes  defective 
in  other  ways. 

The  actual  fixing  on  of  the  face-piece  by  a  screw 
attachment  in  Hewitt's  marks  an  advance,  and 
the  face  itself  is  a  very  good  and  durable  one. 
Some  face-pieces  for  Clover's  inhaler  are  badly 
designed  and  calculated  to  allow  of  leakage. 

The  body  of  the  inhaler  consists  of  a  spherical 
metal  ether  chamber,  upon  one  hemisphere  of 
which  is  fixed  a  water-jacket  to  render  the  tem- 
perature as  constant  as  possible.  The  jacket 
takes  the  form  of  a  cyhndrical  extension.  The 
chamber  is  provided  with  an  aperture  for  intro- 
ducing the  ether,  to  which  is  fitted  a  vulcanite 
stopper  enclosing  a  glass  bulb  indicator. 

When  the  bulb  is  in  the  dependent  position, 
the  ether,  if  any  remain  in  the  chamber,  is  seen 
to  be  there. 

Water-jacket  and  chamber  alike  are  pierced 
by  a  central  tube,  which  has  a  slot  cut  in  it  about 
one-third  of  the  distance  from  either  end,  giving 
access  in  this  way  to  the  ether  contained.  Just 
opposite  these  slots  the  tube  (the  metal  of  which 


ETHER  97 

is  continuous  with  that  of  the  chamber)  is   of 
larger  bore  than  elsewhere. 

A  separate  metal  tube  distinct  from  the  cham- 
ber is  accurately  fitted  into  this  tube  or  outer 
sheath  with  slots  which  correspond  to  those  above 
mentioned,  but  between  them  a  metal  diaphragm 
occludes  the  lumen  of  the  tube.  This  inner  tube 
is  continuous  on  the  one  hand  with  the  face -piece, 
and  on  the  other  with  the  rubber  bag. 

Fixed  on  the  inner  tube  between  the  face-piece 
and  the  water-jacket  is  a  stout  wire  indicator 
which  points  at  figures  marked  on  the  surface  of 
the  water-jacket,  indicating  very  roughly  the 
strength  of  the  vapour  used.  It  really  refers  to 
the  degree  of  coaptation  between  the  slots  in  the 
inner  and  outer  tube,  and  when  they  completely 
correspond  stands  at  F,  or  full.  At  this  point  all 
the  air  inspired  from  the  bag  by  the  patient  passes 
over  the  ether  contained  in  the  metal  chamber, 
and  is  strongly  impregnated  with  ether,  so  much  so 
as  to  be  practically  irrespirable  except  by  a  semi- 
unconscious  patient.  At  0  the  tubes  do  not  coapt 
at  all,  but  all  the  ether  is  shut  in  the  metal  con- 
tainer, none  getting  into  the  patient's  lungs.  It 
cannot  get  past  the  metal  diaphragm,  but  uses  the 
expansion  before  mentioned  in  the  outer  tube, 
which  is  a  sort  of  by-pass;  i,  2,  3,  express  varying 
degrees  of  coaptation. 

7 


98    ANAESTHESIA  IN  DENTAL  SURGERY 

As  a  rule  the  Clover  inhaler  is  made  of  metal  in 
its  entirety.  A  chamber  has  been  put  on  the 
market  by  Maws,  however,  which  is  partly  glass 
and  partly  metal.  The  ether  is  contained  in  a 
spherical  glass  chamber,  on  one  side  of  which  the 
metal  water-jacket  is  fixed  with  plaster  of  Paris. 
This  has  the  advantage  of  allowing  the  adminis- 
trator to  see  what  ether  he  has  to  come  and  go 
on  at  all  times,  and  it  is  a  very  clean  and  pretty 
instrument.  On  the  other  hand,  it  is  more 
fragile.  One  of  us  has  had  one  in  pretty  regular 
use  now  for  over  ten  years,  and  never  had  the 
glass  chamber  broken,  and  if  it  does  break  it  is 
not  expensive  to  replace  Apart  from  any  other 
advantage,  it  is  very  useful  in  getting  students 
and  others  to  understand  the  mechanism  of  the 
Clover  inhaler,  as  they  can  see  most  of  it. 

Hewitt's  Inhaler. — This  differs  from  Clover's 
pattern  in  the  following  particulars: 

1.  The  internal  calibre  is  very  much  larger — 
indeed,  about  twice  the  size  of  the  Clover. 

2.  The  central  tube  rotates  within  the  fixed 
ether  reservoir,  instead  of  the  ether  chamber 
rotating,  as  in  the  Clover  inhaler. 

3.  The  face -piece  is  screwed  on — a  distinct 
advance,  especially  with  nervous  and  alcoholic 
patients  who  struggle. 

4.  The  ether  reservoir  can  be  adjusted  what- 


ETHER  99 

ever  the  position  of  the  patient,  so  that  fresh  ether 
can  be  added  without  suspending  the  administra- 
tion by  removing  the  face-piece  from  the  patient. 
The  inner  tube  is  in  two  sections,  which  are  made 
to  revolve  simultaneously  by  means  of  the  handle, 
which  is  loop-shaped,  with  an  arm  fixed  in  each. 
With  this  apparatus  there  is  less  tendency, 
especially  when  the  administrator  is  inexperienced, 
of  stertor,  cyanosis,  and  laboured  breathing. 
It  has  not,  however,  generally  displaced  the 
Clover,  chiefly,  probably,  as  it  is  rather  more 
expensive. 

The  Administration  of  Ether  by  the  Closed 

Method. 

Where  possible,  it  is  usually  desirable  to  start 
ether  anaesthesia  by  rendering  the  patient  un- 
conscious with  nitrous  oxide  (see  Sequences),  or 
by  a  small  amount  (3  to  5  c.c.)  of  ethyl  chloride; 
but  with  plain  ether  anaesthesia  is  very  easily  and 
rapidly  induced  in  a  Clover's  inhaler  by  any 
adequately  trained  anaesthetist  without  undue  dis- 
comfort to  the  patient.  The  vapour  is,  of  course, 
fairly  pungent  and  the  smell  long  remembered,  and 
usually  detested  after  the  event;  but  it  is  for  the 
administrator  to  see  that  the  vapour  strength  is 
carefully  graduated  so  as  to  cause  as  little  coughing 
and  holding  of  the  breath  as  possible.     This  may 


100   ANAESTHESIA  IN  DENTAL  SURGERY 

be  easily  accomplished  with  the  skilful  manipula- 
tion of  a  Clover,  which  compares  very  favour- 
ably with  the  Ormsby  inhaler  in  this  respect. 
Even  if  nitrous  oxide  precede  ether  given  in  an 
Ormsby,  when  the  gas-bag  is  removed  and  the 
Ormsby  applied  the  breathing  at  once  becomes 
'  choky,'  and  there  is  a  considerable  degree  of 
anoxaemia  and  cyanosis  until  the  patient  becomes 
deeply  anaesthetized  and  air  can  be  freely  per- 
mitted. 

All  this  can  be  avoided  with  Clover's  inhaler. 
It  is  first  charged  with  the  necessary  amount  of 
ether — ^for  dental  work  |  ounce  usually  being 
more  than  sufficient — the  index  set  at  P,  and  any 
ether  vapour  carefully  blown  out  of  the  tube. 

The  face-piece  is  then  carefully  adapted  to  the 
patient's  face.  Care  must  be  taken  there  is  no 
leakage  at  the  upper  extremity  over  the  bridge  of 
the  nose,  where  it  is  most  liable  to  occur,  except  in 
the  case  of  people  with  beards,  when  it  is  always 
difficult  to  prevent. 

In  strong-jawed  muscular  types,  especially  if 
there  are  no  gaps  in  the  front  teeth  already,  it  is 
best  to  start  with  a  small  mouth-prop,  in  order 
to  allow  of  the  mouth  being  readily  opened  with  a 

To  start,  one  or  two  breaths  are  caught  in  the 
bag,  or  the  patient  asked  to  blow  into  it,  and  then 


ETHER  loi 

the  index  is  moved  a  small  fraction  from  zero 
towards  i. 

If  the  patient  breathes  away  comfortably  it 
is  again  advanced,  and  again,  until  i  is  reached. 
If  the  breath  is  held  and  the  vapour  seems  too 
:trong  for  the  patient  at  any  point,  the  index 
needle  should  be  switched  back  J  inch  or  more 
and  a  few  breaths  allowed  of  the  weaker  vapour, 
and  then  another  advance  made.  The  principle 
is  reculer  pour  le  mieux  sauter.  After  such  a  with- 
drawal very  often  a  more  rapid  advance  can  be 
made,  and  the  patient  quickly  becomes  tolerant 
of  stronger  vapours,  and  anaesthetized. 

Unless  the  vapour  strength  be  increased  only 
with  discretion  and  caution,  delay  is  bound  to 
occur  and  very  undesirable  salivation. 

Once  anaesthesia  is  established  and  the  pupil 
fairly  dilated, -3^  to  4!  miUimetres  a  breath  air  to 
3  or  4  of  ether  may  be  usually  allowed  on  principle . 

After-Effects  of  Ether. 
Sickness  is  rather  more  common  than  after 
chloroform,  but  very  transient.  Some  ether- 
impregnated  mucus  and  blood  may  be  rejected  in 
a  few  bouts  of  retching,  and  then  the  patient 
quickly  recovers.  It  is  always  best  that  blood 
should  be  vomited,  as  it  keeps  the  patient  dull 
and  upset  in  his  digestion  if  retained  for  long. 


102  AN.^STHESIA  IN  DENTAL  SURGERY 

Care  must  be  taken  not  to  give  ether  to  people 
with  marked  naso-pharyngeal  catarrh  or  tendency 
to  bronchitis.  Ether  bronchitis  and  pneumonia 
are  rare,  however,  in  healthy  subjects. 

Certain  people  get  very  excited  after  ether, 
alcoholics  and  hysterical  women  in  particular,  and 
some  restraint  in  such  cases  may  be  needed  for  a 
while . 


CHAPTER  VI 

CHLOROFORM 

While  the  field  for  chloroform  in  dental  surgery 
is  extremely  limited,  as  the  indications  given 
below  will  show,  it  is  well  that  its  chemical  char- 
acteristics and  mode  of  action  should  be  referred 
to  briefly  even  in  a  volume  of  this  character.  The 
drug  was  actually  discovered  by  Samuel  Guthrie, 
of  Sacketts  Harbour,  N.Y.,  and  not  by  Simpson,  in 
1831.  Dumas  established  the  chemical  formula 
in  1835,  and  twelve  years  later  Simpson  applied  it 
to  anaesthesia  in  surgical  operations. 

Chloroform  is  a  heavy  liquid  with  a  specific 
gravity  of  1-495  at  62°  F.,  devoid  of  colour  and 
transparent,  and  neutral  in  reaction.  It  has 
an  agreeable  sweet  odour,  quite  unirritating. 

In  the  writer's  own  fairly  extensive  experience 
trouble  during  anaesthesia  is  very  rarely  indeed  due 
to  impure  chloroform.  The  trouble  lies  with  the 
method  of  administration  of  the  drug  or  a  difficult 
subject  for  it  in  the  patient.  Time  and  again  has 
one  of  the  authors  used  chloroform  returned  to 

103 


104  ANESTHESIA  IN  DENTAL  SURGERY 

the  makers  as  '  impure  and  dangerous,'  and  on  no 
occasion  has  any  difficulty  arisen  with  it. 

The  method  of  the  administration  is  simple  in 
the  extreme.  On  the  whole,  the  Schimmelbusch 
mask  is  the  most  convenient  means  of  stretching 
the  hnt  which  is  the  vehicle  for  the  chloroform 
prior  to  its  vaporizing.  The  patient  should  be 
carefully  prepared — more  so  than  with  any  other 
anaesthetic,  and  should  not  be  moved  from  one 
room  to  another  after  the  anaesthesia  is  estab- 
lished. 

Two  layers  of  lint  or  domett  are  stretched  on 
the  Schimmelbusch,  and  a  drop-bottle  of  simple 
character  used;  one  is  easily  improvised  with  a 
3-ounce  fiat  bottle  and  a  perfume  stopper. 

A  httle  vaseline  should  be  placed,  as  a  precau- 
tionary measure,  on  the  most  prominent  part  of 
the  nose  and  chin,  and  perhaps  on  the  cheeks 
of  the  person  to  be  anaesthetized. 

The  dropping  of  chloroform  (which  should  really 
not  occur  when  it  is  properly  administered)  will 
leave  a  mark  of  a  bum  for  some  days. 

The  small  metal  holder  or  handle  of  the  mask 
should  be  held  in  the  administrator's  left  hand 
between  thumb  and  forefinger,  and  a  space  of 
about  I  inch  intervenes  between  the  bottom  of 
the  framework  and  the  face.  This  secures  a  ffee 
supply  of  air,  and  permits  of  the  escape  of  the 


CHLOROFORM  105 

patient's  breath  with  chloroform  and  CO2  therein 
contained. 

In  commencing,  the  mask  is  appHed  for  one  or 
two  breaths;  and  no  chloroform  should  be  put  on 
it,  in  order  to  establish  the  patient's  confidence,  so 
to  speak.  Two  or  three  drops  of  chloroform  may 
now  be  put  on  the  centre  of  the  lint  just  where  the 
supports  of  the  mask  cross  in  the  centre. 

Begin  with  i  drop  every  inspiration,  and  then 
increase  fairly  quickly  to  3  or  4.  It  is  impossible 
to  lay  down  any  definite  rule  to  apply  to  every 
patient.  Each  must  be  judged  on  his  or  her  own 
merits,  and  an  alcohohc,  heavily  built  man  may 
call  for  drachms,  while  a  pale  asthenic  woman 
may  go  under  on  a  minimum  of  drops. 

While  those  not  thoroughly  accustomed  to  the 
drug  must  walk  warily,  there  must  be  no  undue 
dalliance  over  the  early  stages.  It  is  in  the  early 
second  stage  of  struggling  that  dangerous  sjmcope 
sometimes  takes  place.  Care  must  be  taken, 
however,  to  avoid  such  an  increase  of  vapour  that 
the  patient  holds  his  breath  from  its  pungency. 
Delayed  induction  at  the  same  time  may  result 
in  holding  of  the  breath,  with  swallowing  and 
vomiting.  Thus  the  administrator  must  take  the 
via  media,  and  watch  warily  all  the  time.  Let  the 
pulse  not  worry  him.  The  important  thing  is  to 
register  each  respiration  carefully  on   his    tym- 


io6  ANAESTHESIA  IN  DENTAL  SURGERY 

panum,  pajdng  particular  attention  to  its  rhythm 
and  keeping  an  eye  on  the  colour  generally  and 
the  pupil,  to  watch  for  the  onset  of  fiaccidity  in 
the  muscles. 

The  pupil  dilates  at  first  from  the  stimulation 
of  the  sympathetic  nervous  system.  As  con- 
sciousness is  lost  and  the  breathing  deepens,  the 
pupil  gradually  diminishes  in  size  from  stimulation 
of  the  third  or  oculo-motor  nerve;  it  contracts 
down  to  about  2-5  millimetres  diameter,  but  will 
dilate  again  if  the  chloroform  is  unduly  pushed, 
and  a  dilated  fixed  pupil  is  a  danger  signal. 

The  administrator's  objectif  should  be  to  estab- 
lish a  regular  or  automatic  respiration,  a  more  or 
less  fixed  and  contracted  pupil,  complete  muscular 
relaxation,  and  abolition  of  the  corneal  reflex. 
This  last  is  always  a  sign  to  which  students  and 
inexperienced  administrators  attach  undue  value, 
and  damage  is  apt  to  occur  to  the  patient's  sensi- 
tive eye  surface  from  the  constant  and  callous 
probing  of  it  by  the  finger-tip. 

Chloroform  anaesthesia  is  rather  arbitrarily 
divided  into  three  stages,  with  a  fourth  which 
may  be  regarded  as  the  danger  zone.  They  are 
really  not  sharply  defined  one  from  the  other. 

In  the  first  stage  the  patient  rather  resents  the 
application  of  the  vapour,  and  turns  his  face  away, 
possibly  sw^allowing  and  coughing  slightly.     He 


CHLOROFORM  107 

has  a  hammering  or  throbbing  sensation  in  his 
head,  and  is  acutely  sensitive  to  all  noises,  any 
conversation  being  most  undesirable. 

No  operative  procedure  should  be  attempted  at 
this  stage,  which  rapidly  passes  into  the  second. 

In  this  the  patient  has  lost  consciousness,  talks 
rapidly,  shouts  or  swears.  Strugghng  occurs, 
exaggerated  in  the  alcoholic,  and  a  source  of 
danger  and  anxiety  always.  The  patient's  move- 
ments are  restrained,  and  he  finally  loses  his 
breath,  taking  deep,  gasping  inspirations,  which 
may  dangerously  load  his  blood  up  with  chloro- 
form if  the  vapour  be  concentrated. 

Apart  from  struggling,  there  is  danger  of  sick- 
ness at  this  stage,  if  there  be  undue  delay  in 
getting  the  patient  '  under  '  or  into  the  third  stage. 

The  symptoms  of  this  are  almost  unmistakable . 
There  is  regular  automatic  breathing,  loss  of  con- 
junctival reflex,  a  fixed  contracted  pupil,  and 
complete  muscular  relaxation. 

As  regards  the  pupil,  if  it  is  very  small,  under 
2  millimetres,  the  risk  of  the  patient  having 
merely  fallen  asleep  when  half  anaesthetized  has 
to  be  borne  in  mind,  and  some  sharp,  painful 
stimulus,  such  as  a  prick  or  rubbing  roughly  of 
the  external  respiratory  nerve,  be  desirable. 


io8  AN.ESTHESIA  IN  DENTAL  SURGERY 

The  Pupil  in  Anesthesia. 

Three  changes  require  explanation — dilatation, 
contraction,  and  reaction  to  light. 

The  figure  below  gives  a  clear  idea  of  the 
mechanism  we  have  to  rely  on.  First  there  is  the 
sympathetic  nervous  system  supplying  the  long 
ciliary  nerves  to  the  dilators  of  the  pupil,  and 
the  central  nervous  system  supplying  the  short 


Gasserian 

gang/ion 


Superior 
cerv/ca/ 
gangZ/on 


Ophtha/mic  branch  of  fifth  r7erye     ^°'^9  <^'^'ar^ 

nerves 

Di/aior 
pupil lae 


Sphincter 
pupii/as 


-,.,•  />— ^     Short ciiiaru  ner\/e 

L///3ry  ganq//on  ^ 

'  Cervica/ 
Sympathetic 


Fig.   13. — DIAGRAMMATIC   REPRESENTATION  OF   NERVOUS 
MECHANISM    OF    PUPIL. 

ciliary  nerves  to  the  sphincter  pupillae.  The 
mechanism  is  put  in  motion  by  both  stimulation 
and  by  paralysis. 

Stimulation. — Dilatation  occurs  when  the  sym- 
pathetic nervous  system  is  stimulated.  Contrac- 
tion occurs  when  the  central  nervous  system  is 
stimulated  by  light — the  afferent  impulses  travel- 


THE  PUPIL  IN  ANESTHESIA        109 

ling  through  the  retinal  and  optic  nerve,  and  the 
efferent  by  the  cranial  nerve  and  short  ciliary. 

Paralysis. — When  paralysis  of  the  sympathetic 
system  has  taken  place,  the  pupil  contracts  by 
virtue  of  the  tone  of  the  bloodvessels  of  the 
sphincters,  aided  by  the  engorgement  of  the  cihary 
bloodvessels.  When  the  central  system  is  para- 
lyzed, dilatation  takes  place  through  the  elasticity 
of  the  pupil  and  the  emptying  of  the  cihary  blood- 
vessels, which  permit  the  lens  to  bulge  forwards. 
It  is  very  important  to  understand  thoroughly 
the  modus  operandi  as  explained  above. 

Appljdng  this  clinically,  we  find  during  induc- 
tion, the  patient  often  being  excited  and  nervous, 
the  sympathetic  nervous  system  is  stimulated  and 
the  pupils  usually  dilated,  depending  on  the  degree 
of  the  excitement.  As  relaxation  comes  on  the 
sympathetic  becomes  paralyzed  and  the  pupil 
contracts,  but  the  light  reflex  remains. 

During  the  course  of  an  anaesthesia  the  sym- 
pathetic system  becomes  paralyzed,  and  if  deeply 
the  pupil  will  contract  to  2  to  2^  millimetres  and 
not  react  to  sympathetic  stimuli.  The  important 
point  to  observe  and  decide  upon  is  whether 
subsequent  dilatation  is  due  to  returning  con- 
sciousness or  to  deepening  anaesthesia  and  para- 
lytic dilatation  due  to  paralysis  of  the  central 
nervous  system.     If  the  anaesthetic  be  withdrawn 


no  ANESTHESIA  IN  DENTAL  SURGERY 

and  the  pupil  contract,  the  dilatation  is  known 
to  have  been  the  dilatation  of  paralysis. 

When  the  pupil  is  contracted,  with  an  active 
light  reflex,  the  condition  of  the  patient  can  be 
regarded  as  safe,  but  the  anaesthesia  is  not  pro- 
found. 

Blood-Pressure  in  Anesthesia. 

This  is  a  subject  which  has  of  late  attracted 
much  attention,  and  good  work  has  been  done  by 
Guy  Goodall  and  Reid  conjointly.*  Modern 
apparatus,  etc.,  have  made  such  researches  in 
clinical  work  much  more  easy. 

While  the  dental  surgeon  cannot  be  expected 
to  use  a  sphygmomanometer  in  daily  routine, 
some  remarks  on  the  general  aspects  of  the 
question  seemed  called  for  in  a  book  of  this 
character. 

Now,  blood-pressure  may  be  lowered  in  various 
ways:  (i)  By  depression  of  the  heart's  action  by 
vagus  inhibition  direct  or  reflex  (as  in  tooth 
extraction  or  any  painful  stimulus  under  light 
anaesthesia,  especially  chloroform  anaesthesia), 
or  by  weakening  of  the  heart  muscle;  (2)  by 
dilatation  of  the  vessel  wall  or  vaso-motor 
paralysis. 

Blood-pressure  may  be  raised  similarly  by — 

*  Edinburgh  Medical  Journal,  August,  1911. 


BLOOD-PRESSURE  IN  ANESTHESIA     iii 

(i)  Stimulation  of  the  heart  by  excitement — e.g., 
of  the  coming  operation,  or  by  stimulation  of  the 
heart  by  the  drug  used — e.g.,  ether;  (2)  by 
stimulation  of  the  vaso-motor  centres — e.g.,  by 
the  action  of  the  drug  or  by  CO2  in  asphyxia. 

Clinical  study  and  experiment  alike  show  that 
different  anaesthetics  act  on  the  blood-pressure 
in  different  ways,  and  it  has  to  be  borne  in  mind 
that  the  depressing  effect  of  any  anaesthetic  on 
the  blood-pressure  determines  very  largely  the 
relative  danger  of  that  anaesthetic  and  its  tendency 
to  produce  shock. 

Nitrous  Oxide. 

When  given  alone  so  as  to  produce  rapid 
anaesthesia,  this  drug  usually  causes  a  brief 
elevation  of  blood -pressure,  due  to  partial 
asphyxia  or  anoxaemia  induced.  It  is  not  so 
marked  when  rebreathing  is  allowed,  and  is 
almost  completely  eliminated  when  a  gallon  of 
oxygen  is  concomitantly  inhaled.  This  is  a 
point  worthy  of  note  when  dealing  with  apoplectic 
types  of  patients. 

Nitrous  Oxide  and  Ether. 

A  gradual  elevation  of  blood-pressure  is  effected, 
just  as  with  plain  ether.  The  onset  of  shock 
where  the  patient  is  enfeebled  is  d^ayed  or  averted. 


112     ANESTHESIA  IN  DENTAL  SURGERY 

Nitrous  oxide  and  oxygen  causes  a  primary 
rise  in  blood-pressure,  which  immediately  falls  to 
normal  as  the  stage  of  analgesia  is  reached. 

By  the  judicious  use  of  oxygen  any  tendency 
to  elevation  may  be  controlled  almost  indefinitely. 
If  the  oxygen  be  suddenly  increased  or  the  nitrous 
oxide  withdrawn,  a  sudden  marked  elevation  may 
occur  which  persists  for  a  quarter  of  an  hour  or 
more. 

Ethyl  Chloride  and  Somnoform. 

Both  these  drugs  have  been  administered  more 
carefully,  as  already  pointed  out  (p.  92).  Apart 
from  the  tendency  to  spasm  and  asphyxia  which 
we  have  remarked  on,  they  have  .the  effect  of 
powerful  inhibition  of  the  heart  and  bloodvessel 
tone,  causing  a  progressive  fall  of  blood-pressure. 

The  pulse  usually  quickens,  and  a  very  quick 
pulse  may  accompany  a  dangerous  hypotension. 
Oxygen  used  in  combination  with  ethyl  chloride 
tends  to  lessen  this  effect. 

Ether. 
Ether  does  not  cause  any  great  alteration  in 
blood-pressure, -though  there  may  be  a  primary 
rise  or  fall;  usually  there  is  a  pretty  constant 
level  maintained.  The  heart  beats  more  rapidly 
and  more  forcibly  with  some  dilatation  of  the 
smaller  vessels,  the  latter  effect  probably  counter- 


BLOOD-PRESSURE  IN  ANAESTHESIA      113 

acting  the  former.  If  shock  develop  under  ether 
there  is  considerable  concomitant  cardiac  depres- 
sion, and  the  recovery  therefrom  is  slow.* 

Chloroform. 

A  reduction  in  blood-pressure  of  from  10  to  20 
millimetres  Hg  is  usual  with  the  administration 
of  chloroform,  the  degree  largely  depending  on  the 
concentration  of  the  drug.  The  fall  may  occur 
suddenly  and  to  a  dangerous  degree  even  after 
the  administration  of  a  few  cubic  centimetres  of 
chloroform. 

Its  effect  on  blood-pressure  goes  to  confirm  the 
view  that  this  drug  is  dangerous  at  all  stages  of 
its  administration,  the  greatest  danger  being  in 
the  early  stages  of  anaesthesia  and  during  Hght 
anaesthesia,  and  this  danger  is  enhanced  if 
struggling  occur. 

In  what  class  of  case  is  it  permissible,  and  even 
advantageous,  to  administer  chloroform  for  dental 
operations  ? 

The  routine  use  of  chloroform  in  an  extensive 
dental  extraction  is  condemned  in  unqualified 
language  in  these  pages,  but  let  the  reader  make 
no  mistake — neither  of  the  authors  is  an  ether 
faddist,  nor  would  they  hesitate  for  a  moment  to 

*  H.  P,  Fairlie,  Lancet,  February  28,  1914. 

a 


114    AN.ESTHESIA  IN  DENTAL  SURGERY 

use  chloroform  in  a  dental  extraction  in  certain 
circumstances.  It  may  be  necessary  at  times 
for  doctors  in  remote  districts  to  do  the  same 
because  at  the  moment  ether  may  be  unavailable , 
or,  if  the  drug  is  available,  there  may  be  no  inhaler. 
But  apart  from  this  exceptional  circumstance,  it 
may  be  necessary  where  there  are  several  difficult 
teeth  or  stumps  to  remove  from  a  patient  who  has 
some  chronic  heart  or  pleural  trouble  or  abdominal 
growth  of  extensive  proportions,  attended  with 
dyspnoea. 

Further,  when  the  patient  has  been  or  is  insane, 
or  is  subject  to  epilepsy,  on  the  whole  it  is  wiser 
to  give  chloroform,  as  less  liable  to  produce  cere- 
bral vascularity  and  excitement  than  ether  or 
even  nitrous  oxide. 

Insanity  occurs  from  time  to  time  as  a  sequela 
of  all  anaesthetics,  but  probably  fewer  cases  are 
found  to  occur  after  chloroform  than  ether  or 
nitrous  oxide.  One  of  us  has  seen  two  cases  of 
temporary  mental  aberration  after  the  last-named 
anaesthetic,  and  two  of  maniacal  excitement  after 
gas  and  ether  lasting  for  two  hours. 

These  cases,  however,  are  exceedingly  rare,  and 
such  complications  need  only  be  anticipated  in 
highly  neurotic  individuals. 

If  it  seems  advisable,  taking  the  circumstances 
into  account,  to  use  chloroform,  the  chief  points  to 


CHLOROFORM  115 

which  attention  should  be  paid  in  the  administra- 
tion are : 

'  I.  Seeing  that  there  is  a  Hability  when  chloro- 
form is  used  in  dental  operations  for  undetected 
embarrassment  of  breathing  to  arise,  it  is  of  para- 
mount importance  that  the  administrator  should 
make  absolutely  certain,  from  the  commencement 
of  the  administration  till  consciousness  is  restored, 
that  air  is  entering  and  leaving  the  chest. 
Mechanical  obstruction  within  the  air-tract,  from 
the  numerous  causes  which  are  fully  discussed,  is 
very  prone  to  arise,  and  unless  the  administrator 
actually  hears  or  feels  throughout  the  administra- 
tion that  breathing  is  proceeding,  he  will  be  very 
liable  to  be  misled. 

2.  The  administration  should  be  conducted  with 
the  patient  in  the  dorsal  posture,  the  head  and 
shoulders  being  so  adjusted  by  pillows  that  the 
head  is  neither  flexed  nor  extended. 

3.  Owing  to  the  fact  that  breathing  is  liable  to 
become  interfered  with  by  either  extending  or 
flexing  the  head  upon  the  trunk  (a  point  to  which 
the  author  wishes  to  direct  special  attention),  an 
attempt  should  be  made  to  keep  the  head  as  far 
as  possible  in  the  longitudinal  axis  of  the  body. 
Should  it  become  necessary  to  throw  the  head 
well  back,  this  should  be  done  when  the  patient 
is  properly  under  the  anaesthetic,  care  being  taken 


ii6     ANAESTHESIA  IN  DENTAL  SURGERY 

whilst  this  extension  is  present  that  no  blood  or 
extracted  teeth  gravitate  towards  the  now  insensi- 
tive and  open  larynx. 

4.  Care  should  be  taken  during  the  operations 
upon  the  lower  jaw,  or  when  emplo3dng  a  mouth 
gag  or  prop,  that  the  depression  of  the  lower  jaw 
does  not  interfere  with  breathing  by  causing  the 
tongue  to  meet  the  pharjmgeal  wall. 

5.  Intercurrent  asphyxia  from  the  causes  which 
are  given  is  far  more  likely  to  arise  during  light 
than  during  deep  anaesthesia,  so  that  the  ad- 
ministrator should  be  on  the  alert  for  it  just 
as  the  patient  is  entering  and  leaving  the  latter 
state . 

6.  The  patient  should  be  placed  deeply  under 
chloroform  before  any  operation  is  begun.  Should 
any  signs  of  recovery  manifest  themselves  before 
the  operation  is  completed,  care  should  be  taken 
in  reapplying  the  chloroform.  The  patient's  head 
should  be  turned  to  one  side,  a  free  air-way  main- 
tained by  means  of  a  gag,  and  from  this  point 
onwards  only  a  moderately  deep  anaesthesia 
should  be  kept  up. 

7.  Patients  with  naso  -  pharyngeal  adenoid 
growths,  enlarged  tonsils,  or  nasal  polypi,  should 
be  anaesthetized  with  special  care,  owing  to  the 
greater  tendency  to  become  asphyxiated  which 
such  patients  naturally  display. 

8.  At  the  conclusion  of  the  operation  the  patient 


CHLOROFORM  117 

should  at  once  be  turned  upon  his  side,  a  Mason's 
gag  being  placed  between  his  jaws  till  conscious- 
ness is  restored.  The  side  posture  allows  all  the 
blood  to  drain  from  mouth  and  fauces,  the  tongue 
to  gravitate  towards  the  cheek,  and  by  reason  of 
the  free  respiration  established  the  CHCI3  escapes 
from  the  circulation. 

The  rapid  development  of  conservative  dentistry 
during  recent  years  has  struck  a  salutary  blow 
at  the  reckless  and  ruthless  removal  of  decayed 
and  defective  teeth;  but  nevertheless  extensive 
extractions  are  carried  out  in  thousands  of  cases 
annually,  and  familiarity  with  such  a  lethal 
anaesthetic  as  chloroform  has  given  both  practi- 
tioner and  dental  surgeon  a  sort  of  contempt  for 
its  dangers  which  there  is  no  possible  ground  to 
justify.  Very  much  to  the  contrary.  We  pro- 
pose to  enter  into  the  question  of  chloroform  risks 
very  fully. 

In  August,  1895,  the  late  Sir  Frederick  Hewitt 
read  a  most  interesting  paper  before  the  British 
Dental  Association  meeting  at  Edinburgh  on  this 
special  matter.  He  stated  that  he  found  in  ' 
Scotland,  where  chloroform  was  used  as  a  routine 
anaesthetic  in  dental  work,  that  the  ratio  between 
the  number  of  dental  anaesthetic  fatalities  occur- 
ring between  1880  and  1894  inclusive  and  the 
population  was  about  four  times  higher  than  the 
ratio  for  England  and  Wales. 


ii8     ANiESTHESIA  IN  DENTAL  SURGERY 

In  Scotland,  however,  no  coroner's  inquests  are 
held,  and  cases  ending  fatally  are  less  likely  to  be 
made  known  than  in  England,  and  the  proportion 
of  deaths  is  in  all  probability  higher  than  Dr. 
Hewitt  estimates. 


Table  I.  — Deaths  in  Connection  with 
General  Anesthetics  administered  for 
Dental  Operations  in  Great  Britain, 
1880-1894. 


Scotland. 

England 
AND  Wales. 

London. 

Anesthetic  used. 

Approxi- 
mate 
Population, 
4  Millions. 

Approxi- 
mate 
Population, 
23^  Millions. 

Approxi- 
mate 
Population, 
4^  Millions. 

1.  CHCI3 

2.  CHCI3  and  morphia     .  . 

3.  CHCI3,  ether,  mixed    .  . 

4.  Methylene  (really  dilute 

CHCI3) 

5.  Ether     .  . 

6.  Nitrous  oxide   .  . 

12 
I 
0 

0 
0 

I 

15 
0 
I 

2 
I 

2 

0 
0 
0 

0 
0 

2 

14 

21                     2 

Of  the  twenty-seven  deaths  from  CHCI3,  nine- 
teen were  reported  with  sufficient  fulness  to  admit 
of  analysis  and  comparisons  being  made  of  them. 

Sex. — Fourteen  were  females  and  five  males. 
Generally  speaking,  women  take  chloroform  and 
all  anaesthetics  better  than  men. 


Co    BE    MADE.) 


sna. 


Post-mortem. 


Lierved  and  no  pulse  could  be  felt. 
;  then  ceased. 


F<"  suddenly  left  face  and  patient      All  organs  healthy. 


Eith-like,  bluish  pallor  swept  over  i  None. 


^(ithing  were  both  found  to  have 


iame  weak,  a  slight  epileptiform 
ilthough  respiratory  movements 


Flabby,  rather  dilated 
heart.  Valves 
healthy.  Kidneys 
slightly  enlarged  and 
congested.  Other 
organs  healthy. 


iei  fell  back. 
1 


]  turned  pale.  Upon  examination,  Except  a  little  kidney 

felt,  but  breathing  continued  for  disease,     all    organs 

fter  a  few  respirations  the  colour  healthy. 
J  respiration,  but  without  success. 


hiapparently  from  svncope. 
1 


Both  lungs  in  a 
damaged  condition. 
Heart  contracted 
and  empty. 


iSt  cried  out  and  attempted  to  re- 
«olour  became  bluish-white,  the 
(breathing  weak  and  shallow. 


To  face  page  ii3. 


TABLE  II.— BEING  GROUP  I.  OF  THE  TWENTY-SEVEN  CHLOROFORM  FATALITIES. 
(Group  I.  ikl'udes  those  Fatalities,  Nineteen  in  Number,  which  have  been  reported  with  Sufficient  Fulness  to  enable  a  Classification  and  Analysis 'of  them  to  be  made.) 


Classes. 

M.. 

Sex. 

Age. 

General.  Condiliiti.      \          Preparation. 

.„,„., 

Method 
attd  Quantity. 

Relation  of 

Nature  of           ;     Dangerous 

Operation.              Symptoms  to 

\     Operation. 

Phetwmefit^diinng  A  dministration  and  Operation. 

Fatal   Phenomena. 

Post-ntortem. 

m 

ill 

lit 
ill 

^ 

F. 

21 

0£  a  nervous  tempcra- 

Examined,       and 
chloroform    found 
admissible. 

Folded  napkin. 

Large    number    of     During. 
eight  extracted,      j 

Longer  time  than  usual  to  produce  anesthesia.  When  deeply  anaisthetized 
six  or  eight  lower  roots  removed. 

.After  six  or  eight  roots  removed,  pallor  observed  and  no  pulse  could  he  felt. 
No  heart  action  detectable.     Breathmg  then  ceased. 

? 

F. 

About 
35 

Tbin  and  spare;  accus- 
tomed to  faint. 

Clothing      loose. 
No         breakfast. 
Oiieration      11.30 

Recumbent  in  a  chair- 
beneath      shoulders  ; 
othenvise  quite  flat. 

On  napkin. 

of    several    loose 
teeth.         Opera- 

linished. 

Placed  thoroughly  under  the  influence  of  chloroform.  About  one-thu-d  total 
number  of  teeth  removed.  More  chloroform  given.  More  teeth  removed. 
Everything  apparently  going  well.  More  chloroform  given.  Very  little 
hemorrhage  obser\'ed  during  operation. 

After  last  dose  of  chloroform  given,  colour  suddenly  left  face  and  patient  1  All  organs  healthy, 
collapsed. 

I 

^ 

F. 

About 

■  Not  over-robust  Icwk- 

Eighteen         upper  |  Do. 
Three  extracted. 

Diflicult  to  obtain  anajsthesis.  Operation  begun  when  patient  thoroughly 
under. 

Whilst  fourth  root  was  being  removed  a  death-like,  bluish  pallor  swept  over     None. 
face. 

i 

s 
1 

ll 

* 

F.             24 

Very  nervous  and  ex- 
citable. 

taken.'        Corsets 
loosened.       Heart 

Reclining     in     a     low 
easy-chair  with  head 
thrown     well     back- 
pillow  under  back. 

40   or   50   min.   on     For      removal      of 
lint.                                several         teeth. 
Operation        not 
begun. 

Before. 

Inhaled  about  'three  times."  Slipped  forwards  in  chair.  'Head  dropped 
forwards. 

When  she  slipped  forwards,  pulse  and  breathing  were  both  found  to  have 
stopped. 

' 

F.             37 

Healthy  looking,  slout. 
rather  nervous.  Had 
had  severe  neuralgia 
for  two  years.  Heart 
sounds  clear.     Pulse 
good. 

Corsets   and  clothes 
thoroughly 
loosened.        _   Pa- 

Semi  -  recumbent        in 
lowered  dental  chair. 

.iss.   used  on  Skin-  ,  ?  Proposed     opera- 
ner's  inhaler.                 tion.     Operation 
not  begun. 

Respirations  free  and  easy. 

After  30  drops  had  been  given  the  pulse  became  weak,  a  shght  epileptiform 
seizure  took  place,  and  the  heart  failed,  although  respiratory  movements 

continued. 

Flabby,  rather  dilated 

healthy.'       Kidneys 
slightly  enlarged  and 
congested.    Other 
organs  healthy. 

6 

F-               37 

Perfectly  healthy. 

Cautioned     not     to 
take  food. 

About  Siij.  used.       '  ?  Proposed    opera- 
1       tion.     Operation 
not  begun. 

Do.                     Took  it  very  well.     Perhaps  a  little  more  struggling  than  usual. 

Nearly  ready  for  operation  when  she  suddenly  turned  pale.  Upon  examination, 
no  heart  sounds  audible,  and' no  pulse  to  be  felt,  but  breathing  continued  for 
some  time.     Another  account  states  that  after  a  few  respirations  the  colour 
changed,  and  attempts  were  made  to  restore  respiration,  but  without  success. 

Except  a  little  kidney 
disease,     all    organs 
healthy. 

7 

F-               35 

Exlrcmcly   nervous. 

Dress    loose.         No 
food  recently. 

Sitting. 

A  Uttle  over  Jiij.  on     Several  teeth  to  be 

Skinner's  inhaler.         removed.   ?  How 

many   extracted. 

During.              Excited   during   operation,  crying   and   laying   hold   of   operator's  hand. 
Jumped  up.     Struggled  for  two  minutes.     Then  fell  back.     No  reapphca- 
tion  of  chloroform. 

Was  dead  in  less  than  five  minutes  after  she  feU  back. 

? 

8 

F.          Young 

^ 

^ 

' 

?                      Three   teeih   to  be 
removed.        Two 

Do.                      Signs  of  returning  consciousness,  with  raising  of  hands  during  extraction  of 
1       third  tooth.     Only  partially  aniESthetized  throughout. 

Expired  immediately  after  lifting  of  hands,  apparently  from  syncope. 

damaged    condition. 
Heart    contracted 
and  empty. 

M.             11 

Fair;     convalescent 
from  measles. 

Solid       food       four 
hours  before. 

Lying  on  couch.     Head 
and    shoulders 
slighUy  elevated. 

Folded  napkin.             Sis    molars    to    be     Do.                   1  Required  a  good  deal  of  chloroform.     Cried  out  when  operation  begun.  |  Whilst  last  tooth  was  being  extracted  patient  cried  out  and  attempted  to  re- 
extracted.      Five                             ,       More  chloroform  given.     Breathing  norma] .     Pulse  moderate.                            sist.     Just  before  operation  completed  colour  became  bluish-white,  the 
or  SIX  removed.                                 ,                                                                                                                                              patient  became  quiet  and  flaccid,  and  the  breathing  weak  and  sJiallow. 

menu. 


Post-mortem. 


,  and  quickly  died. 


;d,  respiration  and  action  of  heart 
rtificial  respiration  attempted,  but 


d  become  sensitive,  pupils  suddenly 
and  face  blanched.  Although  the 
ns  continued  for  about  two  minutes. 


None. 


peared,  closure  of  eyes  and  spasm  of 
reathing,  were  observed.  Artificial 
tien  it  was  suspended  another  con- 
g  could  not  again  be  started. 


Evidence  of  old  pleu- 
risy. Kidneys,  liings, 
and  liver  congested. 
No  cardiac  disease. 


iver,  pallor  suddenly  occurred,  and      None. 


t  was  observed  to  be  cyanosed  and  Heart  pale  and  flabby. 

for  a  few  minutes  she  gave  a  few  Fatty  infiltration  of 

j  tissues  of  heart  and 

I  body. 


ing  suddenly  ceased ,  pupils  dilated, 
se  was  then  beating  feebly,  but  it 


a  patient  appeared  to  faint.    A  few      Heart    and    lungs 
le  heart's  action  had  failed.  healthv. 


bserved.     Breathing  continued  for 
be  felt. 


None. 


TABLE  11.— BEING  GROUP  I.  OF  THE  TWENTY-SEVEN  CHLOROFORM  FATALITIES— co)i(wMiei. 


Classa. 

No. 

Six. 

.4sc.            General  Conditm;. 

1 

Preparation.                          Posture. 

Method                           Nature  oj 
and  Quantity.        ,          Openitioii. 

Dangerous 
Symptom.'  lo 
Operation. 

Phenomena  during  Administration  and  Operation. 

Fatal    Phenomena. 

P.,.™,.,„. 

'i 
I 

i 

,o 

F. 

i6Io  I7|  Rather  anajmic. 

?                    1  In   dental  chair  placed 
at    about     angle     of 
1       .15  degrees. 

Junker's  inhaler. 

For    sweial    teeth. 
Seven     or    eight 
removed. 

Do. 

Took  it  well.  After  seven  or  eight  teeth  out,  showed  signs  of  recovery.  More 
chloroform  given.     Struggled. 

After  struggling  she  became  opisthotonic,  and  quickly  died. 

' 

" 

M, 

36 

Good;  able  to  undergo 
great  fatigue. 

'  Examined,'        and                         ? 

found    to    be    ad- 
missible. 

?  Proposed  opera- 
removed. 

after"  ^  °^ 

Some  excitement.  Never  entirely  under  influence  of  chloroform.  One  tooth 
and  three  roots  removed.  Patient  quiet  during  operation.  Was  under 
for  five  to  seven  minutes. 

After  one  tooth  and  three  roots  removed,  respiration  and  action  of  heart 
suddenly  ceased.     Face  blanched.     Artificial  respiration  attempted,  but 
could  not  be  induced. 

? 

" 

■'■ 

25 

^ 

■ 

Seated  in  an  easy-chair, 

some  recliniog. 

inhaler.                          moved.      Opera- 
tion completed. 

After. 

Apparently  not  abnormal. 

After  operation  over  and  conjunctiva  bad  become  sensitive,  pupils  suddenly 
dilated,  pulse  became  imperceptible,  and  face  blanched.     Although  the 
heart  could  not  be  felt  beating,  breathing  continued  for  about  two  minutes. 

None. 

" 

F.                   21 

Strong,     full-blooded. 
No   history  of   con- 
vulsions or    fa'mtiiie 
attacks. 

several  hout^. 

'  Was      laid      on      the 

moved.      Opera- 
tion completed. 

Do. 

About  3j.  of  chloroform  required  to  produce  unconsciousness.  After  nine 
teeth  had  been  extracted  from  upper  jaw  patient  showed  signs  of  coming 

After  signs  of  returning  consciousness  appeared,  closure  of  eyes  and  spasm  of 
hands,  arms,  and  legs,  with  arrested  breathing,  were  observed.     Artificial 
respiration  restored  breathing,  but  when  it  was  suspended  another  con- 
vulsive seizure  occurred,  and  breathing  could  not  again  be  started. 

Evidence  of  old  pleu- 
risy. Kidneys,  lungs, 
and  hver  congested. 
No  cardiac  disease. 

1 

A    fresh-coloured  Jad. 
Has    bronchial    ca- 
tarrh in  winter. 

Clotbins    loose    and 

On  table.  Pillow  under 
head. 

Napkin,                          Two     lower,     four 
upper  teeth  to  be 
removed.  Opera- 
tion completed. 

Do. 

Lower  teeth  first  removed.  Durirtg  extraction  of  upper,  patient  cried  out, 
struggled,  and  turned  over  on  liis  side.  Everything  apparently  satis- 
factory. 

Three  to  four  minutes  after  operation  over,  pallor  suddenlv  occurred,  and     None, 
patient  died. 

"1 
111 

.a|S 
■833 

"i  ^" 

.5  go 

ill 
yl 

"  = 

F. 

" 

? 

? 

Skinner's  inhaler. 

Nine  teeth  to  be 
lenioved.     Eight 

During. 

Took  it  well.  Well  under  in  five  minutes.  Dmring  extraction  of  eighth 
tooth  showed  signs  of  recovery.     A  few  drops  more  chloroform  given. 

During  extraction  of  ninth  tooth  patient  was  observed  to  be  cyanosed  and     Heart  pale  and  flabby. 
pulseless.    After  artificial  respiration  for  a  few  minutes  she  gave  a  few         Fatty  infiltration  of 
gasps.                                                                                                                  tissues  of  heart  and 

body. 

16 

F. 

21 

Fairly    nourished. 
Rather    anemic. 
Weak  heart  action. 

Dorsal, 

over  3vj.  used. 

?    Proposed   opera- 

thirteen  teeth  re- 
moved. 

°i;--" 

Took  it  well.  Required  rather  more  than  usual.  After  ten  teeth  had  been 
removed  showed  signs  of  coming  round.  More  chloroform  given. 
Breathing  good  and  regular  up  to  this  point.  No  stertor.  Three  more 
teeth  extracted. 

After  removal  of  last  three  teeth  breathing  suddenly  ceased,  pupils  dilated, 
and  lips  became  sUghtly  livid.     Pulse  was  then  beating  feebly,  but  it 
stopped  within  a  minute. 

'^ 

H. 

33 

Active,  but  not  strons. 

? 

Administered      *  in 
.the  usual  way.' 

One  tooth  and  one 

tracted.  Opera- 
tion completed. 

After. 

Operation  had  just  been  completed  when  patient  appeared  to  faint.    A  few 
respirations  occurred  after  this,  but  the  heart's  aotion  had  failed. 

healthy. 

M. 

Prepared     by     diet. 
Alveolar  abscess. 

Ordinary  easy-chair. 

Towel. 

whole  teeth  re- 
moved. Opera- 
tion completed. 

.. 

After  roots  removed,  struggling  occurred.  More  chloroform  given.  Opera- 
tion successfully  completed. 

When  operation  over,  sudden  pallor  observed.     Breathing  continued  for                        ? 

about  one  minute,  but  no  pulse  could  be  felt. 

19 

F. 

A  barmaid. 

None.       She    was 
wearing         a 

tightly  -fitting 

In  dentist's  chair.              |                 ? 

?                                                                      None. 

CHLOROFORM  119 

Age. — Most  of  the  fatalities  occurred  in  young 
patients,  the  range  being  from  eight  to  thirty-nine 
years. 

General  Condition. — There  was  no  case  in 
which  the  condition  of  the  patient  precluded  the 
use  of  an  anaesthetic  or  rendered  anaesthesia 
perilous.  At  the  present  day  those  competent  to 
judge  consider  that  the  presence  of  cardiac  disease 
or  '  weak '  heart  in  no  way  contra-indicates  the 
employment  of  an  anaesthetic. 

Preparation. — In  a  few  of  the  cases  the  patient 
was  in  no  way  suitably  prepared,  one  being 
attired  in  a  tightly-fitting  dress. 

Summary  of   Objections  to  Chloroform   in 
Dental  Surgery. 

1.  The  known  higher  death-rate,  which,  taking 
into  account  that  a  dental  extraction  is  largely  an 
operation  of  choice  and  not  of  absolute  necessity, 
should  put  chloroform  out  of  court. 

2.  The  tendency  to  syncope  during  chloroform 
anaesthesia  after  struggling,  from  the  erect  posture 
or  from  vagus  inhibition. 

3.  The  short  duration  of  true  anaesthesia  from 
chloroform  and  consequent  need  for  repeated  ad- 
ministration— the  danger  of  vagus  inhibition  and 
*  shock  '  being  greatest  during  light  anaesthesia. 


120     ANAESTHESIA  IN  DENTAL  SURGERY 

If  the  patient  is  bleeding  freely,  the  anaesthetist 
naturally  shrinks  from  deepening  the  anaesthesia, 
and  the  patient  simply  Hes  between  Scylla  and 
Charybdis. 

4.  The  necessity  for  maintaining  the  recumbent 
position  during  chloroform  anaesthesia,  a  position 
most  difficult  for  extraction. 

5.  The  often  prolonged  after-sickness  and  diges- 
tive disturbances  caused  by  inhaling  chloroform. 

6.  The  need  for  thorough  and  careful  prepara- 
tion of  the  patient,  which  often  may  be  done 
without  in  ether  cases. 

We  will  now  endeavour  to  explain  at  length  why 
chloroform  is  essentially  an  unsuitable  anaesthetic 
for  dental  surgery,  and  wherein  the  danger  in 
using  it  in  thi^  department  lies. 

In  the  first  place,  it  is  a  very  great  advantage 
indeed  for  the  operator  to  have  the  patient  who  is 
to  undergo  the  extractions  seated  in  a  dental  chair 
in  a  good,  strong  light,  particularly  if  there  is 
likely  to  be  any  difficulty  with  roots,  etc.  Now,  it 
is  weU  known  that  giving  chloroform  to  a  patient 
in  the  sitting  posture  is  an  extremely  hazardous 
proceeding,  frequently  ending  in  the  death  of  the 
patient  from  syncope,  and  accidents  liave  occurred 
so  often  that  the  practice  has  been  quite  aban- 
doned. The  explanation  af  the  marked  tendency 
to  syncope  lies  in  the  fact  that  chloroform,  more 


CHLOROFORM  121 

than  any  known  agent,  possesses  the  faculty  of 
destroying  the  compensatory  effort  of  nature  for 
the  effect  of  gravity  as  regards  the  circulation. 
Accordingly,  when  a  patient  is  fully  under  its 
influence,  the  arteries  have  little  more  contracti- 
bility  in  them  than  gas-pipes  for  the  time  being, 
and  the  blood  tends  to  gravitate  downwards  and  to 
points  of  least  resistance — e.g.,  the  large  abdominal 
vessels,  or  the  *  abdominal  pool '  of  Leonard  Hill. 
The  brain  and  centres  of  the  respiration  and 
circulation  in  the  medulla  become  anaemic  and 
unable  to  carry  on  their  functions,  and  the  patient 
collapses  and  dies  of  syncope. 

Out  of  716  deaths  under  chloroform  recorded  in 
the  Lancet  clinical  report,  fifty-six  occurred  during 
the  extraction  oi  teeth,  and  in  the  bulk  of  these 
the  patient  was  in  the  sitting  position. 

The  recumbent  position,  then,  is  an  absolute 
essential  to  the  safety  of  the  patient,  but  from  the 
point  of  view  of  the  operator  most  unsuitable. 
Further,  in  this  position  there  is  another  element 
of  risk  to  be  considered — viz.,  teeth  or  roots 
slipping  from  the  forceps  and  passing  into  the 
respiratory  passages — an  accident  more  likely 
than  when  the  patient  is  sitting  up. 

In  investigating  the  relative  mortality  of  ether 
and  chloroform,  we  have  evidence  obtained  from 
the    Physiological   Laboratory,    due    to    the   re- 


122     ANAESTHESIA  IN  DENTAL  SURGERY 

searches  of  Coates,  Leonard  Hill,  Mc William,  and 
others,  and  also  abundant  clinical  evidence,  to 
weigh  down  the  balance  in  favour  of  ether.  The 
conclusion  of  the  late  Professor  Coates,  as  far  as 
laboratory  results  are  concerned,  was  that  '  he 
was  firmly  convinced  from  multiplied  experiments 
that  ether  exercises  much  less  of  a  paralyzing 
action  on  the  intrinsic  ganglia  of  the  heart  than 
chloroform  does,'  and  '  that,  as  far  as  laboratory 
experiments  were  concerned,  ether  came  out 
distinctly  better  than  chloroform.' 

It  is  found  that  death  during  the  administra- 
tion of  chloroform  is  due,  in  the  large  majority  of 
cases,  to  cardiac  syncope,  which  may  arise  from : 

1.  Reflex  stimulation  of  the  vagus,*  causing  in- 
hibition of  the  cardiac  pulsations;  this  occurs  in 
light  anaesthesia,  due  to  insufficient  chloroform. 

2.  Depressant  action  of  the  chloroform  on  the 

*  Although  in  the  experiments  carried  out  by  the 
Hyderabad  Commission  on  dogs  and  monkeys  reflex 
inhibition  of  the  vagus  was  not  found  to  occur,  in  man  it 
must  be  accepted  as  a  fact.  Dudley  Buxton  states  that 
his  own  experience  enables  him  to  speak  dogmatically 
on  this  point,  for  he  has  again  and  again  seen  the  circu- 
lation and  respiration  both  profoundly  interfered  with 
by  reflexes  when  a  patient  has  been  under  the  influence 
of  chloroform.  In  dental  operations,  where  the  shock 
occasioned  by  the  laceration  of  the  branches  of  the  fifth 
or  trifacial  nerve  is  out  of  all  proportion  to  the  severity 
of  the  undertaking,  there  is  an  especial  danger  of  primary 
cardiac  failure  through  reflex  cardiac  inhibition. 


CHLOROFORM  123 

medullary  centre  of  the  heart,  the  vaso-motor 
centre,  the  intrinsic  ganglia,  and  on  the  myo- 
cardium itself. 

Death  in  this  manner  is  due  to  overdose — of 
course,  overdose  is  purely  a  relative  term — in 
regard  to  which  the  personal  equation  must  bulk 
very  largely. 

While  death  is  most  commonty  due  to  heart 
failure  of  circulation,  it  may  be  due  to  cessation  of 
respiration  occurring  in  three  separate  ways : 

1.  Direct  obstruction  from — 

{a)  Laryngeal  stertor,  due  to  spasm  and 
approximation  of  aryepiglottidean 
folds. 

(b)  Falling  back  of  the  tongue. 

2.  Direct  retardation  and  arrest  of  the  pul- 
monary circulation — first  in  the  capillaries  and 
later  in  the  larger  vessels — due  to  the  direct  local 
action  of  chloroform. 

3.  Interference  with  the  respiratory  centre  in 
the  medulla  and  the  subordinate  centres  in  the 
spinal  cord. 

With  reference  to  the  last,  we  must  bear  in 
mind  that  in  chloroform  we  have  a  drug  which 
acts  by  temporarily  paralyzing  the  nerve-centres. 

The  higher  centres  it  is  our  object  and  desire  to 
paralyze,  but  we  have  only  to  go  a  step  further  to 


12  4   AN.ESTHESIA  IN  DENTAL  SURGERY 

produce  a  similar  effect  on  those  governing  the 
vital  processes. 

We  thus  observe  that  chloroform  kills  in  two 
distinct  ways  by  its  action:  (i)  on  the  circulation, 
(2)  on  the  respiration. 

Probably  these  actions  are  frequently  combined 
and  occur  simultaneously.  There  has  been  much 
useless  controversy  on  the  subject. 

Examining  the  manner  by  which  a  fatal  issue  is 
arrived  at  with  ether,  we  find  the  possibilities,  and 
consequently  the  likelihood,  of  a  fatal  tissue  much 
less  numerous. 

Death  may  arise  from  cessation  of  respiration 
due  to : 

1.  Direct  obstruction  from  laryngeal  spasm, 
falling  back  of  tongue,  etc. 

2.  Spasmodic  contraction  of  respiratory 
muscles,  arising,  as  a  general  rule,  from  overdose 
— a  very  unlikely  event  if  reasonable  care  be 
exercised,  the  patient  watched,  and  cyanosis 
avoided. 

The  modus  operandi,  as  in  the  case  of  chloroform, 
is  the  paralysis  of  the  respiratory  centres,  due  to 
overloading  of  the  blood  with  ether;  and  there  is, 
as  a  general  rule,  ample  time  for  the  avoidance  of 
a  fatal  issue  by  the  use  of  artificial  respiration. 

With  chloroform,  however,  when  the  blood  is 
so  saturated  as  to  cause  paralysis  of  the  respira- 


CHLOROFORM  125 

tory  centres,  the  circulatory  centres  will  be  very 
seriously  interfered  with,  if  not  already  paralyzed, 
and  satisfactory  result  from  the  application  of 
restorative  measures  is  less  likely  on  this  account. 

Syncope  during  the  administration  of  ether  is 
almost  unknown.  The  drug  is  itself  a  cardiac 
stimulant,  and  if  heart  failure  does  occur,  it  is  due 
to  some  constitutional  dyscrasia  or  to  lowered 
vitality. 

We  would  naturally  expect  from  the  respective 
actions  of  chloroform  and  ether,  as  briefly  stated 
above,  that  fatalities  would  be  more  frequent  in 
the  case  of  chloroform,  and  our  expectations  are 
borne  out  by  clinical  results.  Many  statisticians 
have  laboured  at  the  subject  during  the  past  half- 
century,  but  it  is  not  necessary  to  enter  into 
their  special  findings  in  any  great  detail  in  this 
work. 

Roughly,  the  mortality  under  chloroform  is 
I  in  1,000,  and  that  of  ether  i  in  10,000.  The 
records  of  a  very  large  general  hospital  in  London, 
where  the  anaesthetics  are  administered  by  highly 
trained  anaesthetists,  over  a  period  of  twenty-five 
years  give  the  following  results : 

Chloroform  given  37,914  times,  29  deaths  ==i  in    1,331. 
Ether  „      32,674      „         3       „      =1  in  11,262. 

Thus  it  is  demonstrated  that  in  a  hospital  where 
the  anaesthetics  are  given  with  a  very  high  degree 


126     ANAESTHESIA  IN  DENTAL  SURGERY 

of  skill  fatalities  under  chloroform  are  just  nine 
times  as  numerous  as  those  of  ether. 

The  death-rate  under  nitrous  oxide  is  low  in  the 
extreme,  being  about  i  in  10,000;  ethyl  chloride, 
I  in  15,000. 

Thus  it  is  apparent  that  a  medical  practitioner 
who  ignores  these  facts  and  persists  in  giving 
chloroform  for  dental  operative  procedures,  be- 
cause he  is  too  old  or  too  lazy  to  adopt  more 
modern  methods,  is  not  only  deserving  of  the  severe 
censure  of  his  fellows  and  his  patients,  but  really 
merits  the  attention  of  the  General  Medical 
Council:  w^ehad  almost  said  the  Public  Prosecutor. 
The  public  are  getting  to  learn  the  facts  of  the  case, 
and  to  know  how  to  protect  themselves  in  many 
cases.  The  less  well  informed  may  become  vic- 
tims, but  those  who  victimize  them  deserve  the 
very  strongest  condemnation. 

Death  from  an  anaesthetic  is  a  very  different 
thing  from  death  iinder  an  anaesthetic.  In  the 
first  case  the  drug  is  the  principal  cause;  in  the 
second  the  actual  cause  of  death  may  be  some- 
thing widely  different. 

No  anaesthetic  has  been  yet  discovered  which 
is  entirely  free  from  danger  under  any  circum- 
stances. A  person  in  ordinary  health  requiring  a 
minor  operation,  such  as  the  extraction  of  several 
teeth,  takes  a  few  whiffs  of  chloroform,  and  with 


CHLOROFORM  127 

little  or  no  warning  turns  pale,  his  pulse  and 
breathing  stop,  and  he  dies.  A  post-mortem 
examination  fails  to  show  any  adequate  physical 
or  pathological  cause  for  death,  and  the  only  con- 
clusion to  be  arrived  at  is  that  the  substance  used 
to  induce  anaesthesia  was  the  actual  cause. 

Pure  ether,  skilfully  administered,  never  kills 
healthy   people.     Chloroform   occasionally   does, 
and  in  the  manner  and  under  the  circumstances 
we  have  above  described.     About  40  per  cent, 
of  the  fatalities  which  occur  under  chloroform 
take  place  in  reasonably  healthy  persons  under- 
going operations  of  a  minor  character  without  any 
element  of  danger.     These  deaths  commonly  occur 
in  the  early  stages  of  anaesthesia  before  the  patient 
is  really  *  under,'  and  very  often  in  subjects  who 
have  previously  taken  the  drug  quite  well.     No 
blame  can  be  attached,  in  the  vast  majority  of 
instances,  to  the  quality  of  the  chloroform,  very 
seldom  to  the  actual  method  of  administration. 
These  accidents  have  occurred  in  the  hands  of 
men    like    Simpson,    Syme,    Erichsen,    Hunter 
Maguire,   and  many  highly  trained   specialists. 
Surely,  then,  an  agent  not  safe  in  the  hands  of  men 
like  these  cannot  and  certainly  should  not  he  relied 
on  by  the  average  medical  practitioner  for  the  pro- 
duction of  ancBSthesia  for  ordinary  routine  dental 
extractions f  as  in  some  parts  of  Scotland. 


128    ANESTHESIA  IN  DENTAL  SURGERY 

It  is  the  toxic  nature  of  chloroform,  and  the 
capricious  way  in  which  it  acts  on  different  people, 
which  constitute  its  chief  danger.  Ether  is  never 
uncertain  in  its  action.  It  has  its  disadvantages 
and  contra-indications,  but  there  is  always  plenty 
of  warning  of  any  difficulty,  and  ordinary  restora- 
tive measures  taken  in  time  amost  always  over- 
come the  trouble. 

The  onset  of  dangerous  symptoms  in  chloroform 
anaesthesia  is  terribly  sudden,  and  in  the  majority 
of  cases  of  true  chloroform  syncope  occurring 
during  the  early  stages  all  efforts  to  restore 
animation  are  entirely  useless. 

Repeated  controversies  have  been  carried  on  in 
the  medical  journals  and  elsewhere  as  to  whether 
the  heart  or  the  breathing  stopped  first,  but  have 
resulted  in  little  profit  to  anyone.  It  makes  no 
difference  to  the  patient  or  his  friends  which 
stops  first;  the  result  in  any  case  is  too  often 
disastrous. 

In  spite  of  the  most  painstaking  investigation 
of  the  whole  question  of  chloroform  anaesthesia  by 
individuals  and  commissions,  the  practical  fact 
stands  out  with  terrible  distinctness  that  the 
death-rate  from  chloroform  has  not  decreased, 
but  increased,  and  markedly  so. 


CHAPTER  VII 
SEQUENCES  AND  COMBINATIONS 

Nitrous  Oxide  and  Oxygen. 

It  has  been  quite  a  common  thing  for  anaesthetists 
and  dental  surgeons  to  notice  with  some  amuse- 
ment the  alarm  engendered  in  patients'  friends — 
if  present  at  a  nitrous  oxide  case — and  even  in  the 
family  practitioner,  by  the  somewhat  horrific 
aspect  assumed  by  the  person  anaesthetized,  with 
the  deep  cyanosis  and  facial  contortion. 

We  have  personally  known  the  doctor  to  be  on 
the  point  of  intervening  to  protect  his  patient 
and  cry  "  Hold  !  enough  !"  fearful  of  a  cerebral 
haemorrhage  or  complete  asphyxia. 

Possibly  this  drawback  to  nitrous  oxide  pure 
and  simple  led  to  attempts  to  induce  a  more  tran- 
quil and  pretty  anaesthesia  by  other  means,  and 
the  first  step  towards  an  oxygen  and  NgO  com- 
bination was  the  allowance  of  an  admixture  of  air 
given  in  the  proportion  of  25  per  cent.,  or  one 
breath  of  air  in  every  five  inspirations.  This  is 
attributed  both  to  the  late  Mr.  George  Rowell  and 

Mr.  Carter  Braine. 

129  9 


130    AN.ESTHESIA  IN  DENTAL  SURGERY 

Nitrous  oxide  and  oxygen  anaesthesia  has  ac- 
quired during  the  war  an  importance  and  a  degree 
of  general  recognition  which  was  anticipated  only 
by  those  few  who  in  this  country  and  the  U.S.A. 
had  been  working  for  some  years  to  perfect  its 
administration.  Brief!}/  put,  its  advantages  over 
other  ansesthetics  are  as  follows: 

(a)  It  protects  the  patient  from  surgical  shock 
much  more  effectively  than  does  any  other  anaes- 
thetic. 

{b)  It  is  non-toxic.  The  patient  recovers  in  a 
few  minutes  from  the  longest  inhalation,  with  his 
tissues  and  his  metabolic  processes  unaffected  by 
the  drug.  He  can  take  full  nourishment  from  the 
very  inception  of  his  convalescence.  All  this  is 
in  strong  contrast  with  ether  and  chloroform,  after 
either  of  which  he  has  to  pass  through  a  period 
of  depression  and  nausea,  etc.  On  the  other  side 
of  the  account,  we  must  admit  that  the  method  is 
costly  and  the  apparatus  cumbersome  and,  in  its 
most  highly,  developed  forms,  almost  immobile. 
These  factors  have  not  in  this  war,  however, 
prevented  a  wide  use  of  the  method,  which  has 
been  of  untold  help  to  great  numbers  of  our  men, 
particularly  those  most  severely  wounded  and 
most  heavily  infected  with  sepsis.  To  say  that 
all  this  does  not  concern  the  dental  surgeon  in  his 


SEQUENCES  AND  COMBINATIONS     131 

professional  capacity  is  to  take  a  very  partial 
view  of  the  case.  Judgments  and  valuations 
formed  at  the  Front  come  home  with  the  men 
who  formed  them,  and  in  the  near  future  we  may 
expect  to  see  a  genuine  demand,  both  from  sur- 
geons and  patients,  for  a  more  extended  use  of 
gas-oxygen.  In  the  response  to  this  demand,  the 
progressive  dental  surgeon  will  naturallj^  wish  to 
take  his  due  part. 

The  inquirer  into  this  branch  of  anaesthesia  is 
met  at  the  very  threshold  by  the  difficulty  in 
selecting  an  apparatus  good  in  itself,  and  suitable 
for  his  requirements;  and  is  apt  to  lose  himself 
in  a  mass  of  makers'  catalogues  and  pamphlets 
specially  written  to  extol  the  virtues  of  one  parti- 
cular machine.  Perusal  of  this  literature  without 
a  good  preliminary  grasp  of  root  principles  tends 
to  involve  the  whole  subject  in  confusion  and  to 
make  it  appear  much  more  complicated  than  it 
really  is. 

The  names  of  the  different  gas-oxygen  appara- 
tuses are  legion,  their  appearances  most  diverse, 
but  the  underlying  principles  are  few  and  simple. 
An  article  written  in  1914  by  one  of  us  ("The 
Edinburgh  System  of  Dental  Anaesthesia," 
British  Dental  Journal,  1914,  p.  458  et  seq.) 
reduced   the    then  recognized  methods  to   four, 


132  ANAESTHESIA  IN  DENTAL  SURGERY 

to  which  a  fifth  must  now  be  added.     They  are 
as  follows : 

Hewitt's  original  method. 

Tcter's  method. 

The  Guy-Ross  method. 

Gatch's  method   (not  here  to  be  described, 

but   in  some  sense  the  forerunner  of  the 

Guy-Ross). 
Sight-feed  machines. 

Hewitt's  Method. 

About  1886  the  late  Sir  F.  W.  Hewitt  started 
working  at  a  combined  gas  and  oxygen  apparatus, 
and  designed  one  which  would  permit  of  an  ap- 
proximately definite  percentage  of  oxygen  to  be 
given. 

Rumbold  of  Leeds  worked  at  the  same  subject, 
and  designed  a  similar  apparatus,  but  with  two 
bags. 

Hewitt's  complete  apparatus  consists  of  two 
nitrous  oxide  cylinders  and  one  of  oxygen,  with 
a  combined  stand  and  union  and  double  or 
centrically  arranged  rubber  tubes  for  conducting 
the  gases  from  the  cylinders  to  the  bags.  The 
bags  are  really  formed  by  putting  a  septum  in  one 
bag,  and  are  connected  with  a  regulating  stop-cock, 
mixing  chamber,  and  face-piece.  Nitrous  oxide 
cylinders  of  50-gallon  size  are  most  convenient, 
one  of  these  holding  about  15  gallons  of  oxygen. 


SEQUENCES  AND  COMBINATIONS     133 

The  foot-key  of  the  NgO  cylinder  being  turned 
on,  the  gas  passes  to  its  special  section  of  the  bag 
through  brass  and  rubber  tubes  of  fairly  large 
caHbre.,  The  tube  for  the  oxygen  is  of  smaller 
size,  and  lies  within  the  other. 

The  compartments  are  of  equal  size,  and  are 
only  separated  by  a  common  indiarubber  septum. 
When  filled  they  appear  almost  like  a  single  bag. 

The  regulating  stop-cock  and  mixing  chamber 
are  figured  opposite. 

The  valves  are  made  of  thin  sheet -rubber,  and 
the  same  remarks  that  were  made  about  those  in 
the  ordinary  nitrous  oxide  apparatus  apply  to 
them. 

They  are  arranged  to  act  most  efficiently  when 
the  main  expiratory  valve  is  kept  as  horizontal  as 
possible.  If  the  patient's  head  is  thrown  far  back 
and  the  apparatus  tilted,  they  will  not  act  so  well. 

The  production  of  anaesthesia  by  means  of 
nitrous  oxide  and  oxygen  is  a  most  delicate  pro- 
cess, much  more  so  than  simply  administering 
nitrous  oxide,  and  the  most  trifling  defects  in 
the  apparatus  are  liable  to  interfere  with  results. 
Great  care  is  needed  in  putting  the  apparatus 
together,  in  handling  it,  and  seeing  that  it  is  in 
perfect  working  order. 

In  regard  to  the  relative  proportions  of  nitrous 
oxide  and  oxygen  which  the  apparatus  is  capable 


134    AN.ESTHESIA  IN  DENTAL  SURGERY 

of  furnisliing,  much  will  depend  on  the  degree  of 
distension  of  the  bags  during  the  inhalation, 
whether  they  are  kept  of  the  same  size  or  not, 
and  at  the  same  time  each  apparatus  possesses 
slight  peculiarities  of  its  own. 

Hewitt's  original  pattern  of  gas  and  oxygen 
apparatus  had  two  separate  bags  and  tubes, 
and  Rumbold's  apparatus  is  now  made  in  this  way. 

The  apparatus  is  necessarily  more  bulky  and 
unwieldy,  but  is  less  likely  to  get  out  of  order  than 
the  new  pattern,  in  which  the  occurrence  of 
leakage  from  bag  to  bag  through  the  septum  is 
difficult  to  detect,  and  may  cause  confusion  and 
lead  to  poor  results. 


The  Administration. 

The  bags  should  be  half  filled  with  their  respec- 
tive gases,  and  the  face-piece  very  carefully  ad- 
justed. The  patient  is  instructed  to  breathe 
freely  in  and  out  through  the  mouth,  and  when 
good  breathing  has  been  established  the  indicator 
should  be  turned  to  '2.'  Nitrous  oxide  with 
2  per  cent,  of  oxygen  is  then  being  administered. 
If  a  large  percentage  of  oxygen  is  given  at  the 
start,  excitement  is  apt  to  occur.  In  two  or  three 
seconds  the  indicator  may  be  turned  to  '3,'  and 
then  to  '  4,'  the  bags  being  meantime  kept  as 


SEQUENCES  AND  COMBINATIONS     135 


^^ 


FIG.   14. — Hewitt's  gas  and  oxygen  apparatus. 


1-/)   AN.ESTHESIA  IN  DENTAL  SURGERY 


AH 


FIG.  15. — Hewitt's  gas  and  oxygen  stop-cock  in  pieces. 
(From  Hewitt's  '  Gas  and  Oxygen,'  Ash.) 

NOT,  Nitrous  oxide  tube;  NOO,  orifice  of  same;  SS,  sup- 
plementary stop-cock ;  C,  chimney ;  Figures,  per  cent, 
of  oxygen;  OT,  oxygen  tube;  OO,  orifice  of  oxygen 
tube;  ID,  inner  drum;  AH,  air  hole;  IV,  main  in- 
spiratory valve;  EV,  main  expiratory  valve;  H, 
handle  with  indicator;  S,  slot. 


SEQUENCES  AND  COMBINATIONS    137 

nearly  as  possible  of  equal  size.  It  is  rarely 
necessary  to  have  to  turn  on  more  oxygen  during 
an  ordinary  dental  case,  but  more  nitrous  oxide 
is  always  required.  If  phonation  or  excitement 
occurs,  the  oxygen  must  on  no  account  be  in- 
creased, but  diminished.  Working  the  indicator 
on  gradually  in  the  course  of  the  first  minute,  it 
should  have  got  to  about  '  8,'  and,  as  a  rule,  a 
higher  percentage  than  this  is  not  required  in 
dental  work. 

In  female  subjects  and  children  this  percentage 
will  frequently  be  used,  but  for  robust  people  a 
smaller  percentage  wiU  be  followed  by  better 
results. 

The  Period  of  Inhalation  of  Nitrous  Oxide 
AND  Oxygen. 

The  time  needed  to  secure  a  deep  degree  of 
anaesthesia  varies  with  different  cases. 

Sir  F.  W.  Hewitt,  however,  over  a  series  of  very 
carefully-timed  administrations,  found  the  period 
to  be  110-5  seconds  on  the  average,  and  the  corre- 
sponding period  of  available  anaesthesia  averaged 
44  seconds. 

We  thus  find  that,  while  just  double  the  time 
is  required  as  compared  with  nitrous  oxide  the 
anaesthesia  obtained  is  only  half  as  long  again  in 
duration. 


13^    ANESTHESIA  IN  DENTAL  SURGERY 

Recovery  of  Consciousness 

takes  place  more  gradually  than  with  nitrous 
oxide.  The  patient  is  usually  a  little  more  dazed, 
and  nausea,  or  even  vomiting  and  headache,  are 
more  common  than  after  the  inhalation  of  nitrous 
oxide  gas  alone.  Pallor,  feeble  pulse,  and  faintness 
occasionally  occur.  Hewitt  noted  three  cases  of 
transient  maniacal  excitement. 

The  Advantages  and  Disadvantages. 

When  the  patient  is  over  sixty,  has  cardiac 
disease  with  imperfect  compensation,  is  suffering 
from  phthisis,  or  is  very  run  down  and  anaemic, 
there  is  unquestionably  a  very  distinct  gain  in 
combining  oxygen  in  some  proportion  with  the 
*  laughing-gas.'  Hewitt's  apparatus  enables  us 
to  do  this  in  a  fairly  definite  way,  as  we  know 
approximately  the  percentage  of  oxygen  we 
are  using.  But  practically  one  finds  in  dealing 
with  such  cases,  that  the  ordinary  nitrous  oxide 
apparatus  with  a  bottle  of  oxygen,  fitted  on 
the  stand  and  used  at  discretion,  answers  every 
purpose. 

Oxygen  may  also  be  administered  along  with 
nitrous  oxide  when  using  Paterson's  apparatus, 
the  administrator  gauging  the  amount  of  oxygen 
by  the  patient's  condition,  degree  of  cyanosis,  etc. 


SEQUENCES  AND  COMBINATIONS    139 

The   great   bulkiness   of  the   gas  and  oxygen 
apparatus  is  certainly  a  drawback.     The  two  dis- 


FIG.    1 6 


;R0SS-SECTI0N    of    HEWITT  S    NgO    AND 
OXYGEN    BAG. 


tended  bags  are  apt  to  frighten  nervous  children, 
and  the  apparatus  as  a  whole  is  certainly  more 
apt  to  get  out  of  order  than  the  ordinary  single 


140   AN.^STHESIA  IN  DENTAL  SURGERY 

gas  apparatus.  Further,  it  requires  just  as  much 
practice  to  skilfully  use  the  combined  gases  as  to 
master  the  use  of  Paterson's  nasal  apparatus,  an 
infinitely  more  portable  and  convenient  mechan- 
ism, and  one,  moreover,  by  which  unlimited  quan- 
tities of  air  01  oxygen  can  be  made  use  of,  and  an 
anaesthesia  of  from  half  a  minute  to  five  minutes 
or  more  readily  obtained  after  a  reasonable 
amount  of  experience  and  practice. 

The  Teter  System. 
Teter  brought  out  his  machine  in  the  first 
decade  of  this  century.  In  it  he  introduced  an 
entirely  new  principle.  He  removed  the  inspira- 
tory valve  from  the  mouth  of  the  nitrous  oxide 
bag,  and  designed  the  expiratory  valve  to  open 
against  a  slight  spring  resistance,  which  resistance 
can  be  increased  or  decreased  at  w411.  Observe 
the  results  of  this  alteration  of  Hewitt's  original 
scheme,  and  the  added  powers  which  it  puts  into 
the  hands  of  the  administrator.  Firstly,  by 
maintaining  a  full  flow  of  gases  from  the  cylinders, 
while  at  the  same  time  increasing  the  resistance 
against  which  the  expiratory  valve  has  to  open,  it 
is  possible  to  maintain  a  certain  positive  pressure 
of  the  gases  upon  the  patient.  A  very  little 
experience  will  convince  an  observer  that  in  this 
positive  pressure  he  has  put  at  his  disposal  a 


SEQUENCES  AND  COMBINATIONS    141 

potent  means  of  deepening  gas-oxygen  anaesthesia 
to  a  degree  not  possible  without  such  help.  That 
the  method  is  capable  of  abuse  and  can  be  pushed 
a  dangerous  degree  is  obvious,  but  is  no  argu- 
ment against  its  proper  use  in  skilled  hands. 
Secondly,  by  reducing  the  flow  of  gases  while 
maintaining  the  tension  of  the  expiratory  valve, 
it  is  possible  to  cause  part  of  each  expiration  to 
return  into  the  nitrous  oxide  bag  (which  it  will  be 
remembered  is  unguarded  by  an  inspiratory  valve) . 
By  delicate  manipulation  of  the  two  factors — 
tension  of  valve  of  expiration  and  the  flow  of  gases 
from  the  cylinder — it  is  easy  for  the  expert  to 
arrange  for  just  that  degree  of  rebreathing  which 
is  beneficial  to  the  patient,  and  having  reached 
the  correct  adjustment,  to  maintain  a  good,  even 
anaesthesia  without  further  tap-handling.  This 
was  undoubtedly  a  great  advance. 

Designing  his  machine,  as  he  did,  on  a  sub- 
stantial stand,  not  intended  to  be  carried  about 
from  house  to  house,  Teter  had  room  for  several 
useful  additions,  notably  a  chamber  in  which  the 
gases  are  heated  before  being  inhaled,  and  another 
in  which  a  little  ether  vapour  may  be  added  to 
the  gases  in  cases  where  such  addition  was  con- 
sidered desirable. 

Numerous  other  American  machines  have  been 
introduced,  containing  the  same  principles.     Of 


142   AN.ESTHESIA  IN  DENTAL  SURGERY 

these  we  shall  mention  two.  The  Clarke  was 
devised  especially  for  administration  of  the  gases 
by  the  nasal  method,  the  maker's  pamphlet 
advocating  its  use  for  the  production  of  the  state 
known  as  analgesia.  This  is  a  stage  reached 
before  the  loss  of  consciousness.  In  it  sensitive 
dentine  can  be  drilled  and  even  live  pulp  cavities 
cleaned  out,  without  the  causation  of  pain  to  the 
patient.  By  using  a  mixture  rich  in  oxygen 
delivered  at  low  pressure,  the  state  of  analgesia 
can  be  prolonged  for  a  considerable  time.  It  is 
obvious  that  the  least  change  in  the  conditions, 
however,  may  carry  the  patient  into  anaesthesia, 
a  point  with  which  one  has  to  reckon. 

The  Chio  machine  represents  another  recent 
attempt  to  improve  gas-oxygen  methods.  In  this 
instrument  the  essential  point  is  the  introduction 
between  the  cylinder  heads  and  the  reservoir  bags 
of  pressure  gauges,  and  of  means  to  dam  back  the 
flow  of  gases,  and  thus  to  produce  a  more  even 
flow  into  the  reservoir  bags.  When  acting  well, 
this  system  certainly  gives  more  security  than 
others  for  the  maintenance  of  a  level  anaesthesia, 
but  all  depends  upon  the  gas-tightness  of  the 
connections — not  an  easy  point  upon  which  to 
be  sure  of  uniform  success.  Probably  the  easiest 
way  to  secure  the  desired  steadiness  of  flow  with 
any  machine  is  to  use  cylinders  of  large  capacity. 


SEQUENCES  AND  COMBINATIONS    143 

and  to  make  provision  for  warming  the  heads  of 
the  cyHnders.     Freezing  of  the  orifices  through 
which  the  gases  flow^  is  fatal  to  evenness  of  flow. 
All  the  machines  so  far  mentioned  in  this  group 
are  large  and  not  intended  for  moving  from  house 
to  house.     An  attempt  has  been  made  to  modify 
the  Hewitt  instrument  so  as  to  combine  its  com- 
parative mobility  with  the  advantages  of  the  new 
principles  introduced  by  Teter.     This  has  been 
done  by  removing  the  inspiratory  valve  from  the 
mouth  of  the  nitrous  oxide  bag,  and  fitting  the 
expiratory  valve  w4th  a  cap,  which  can  be  rotated 
in  such  a  w^ay  as  to  put  the  valve  out  of  action 
altogether     when    desired.      This    modification, 
known  as  Burn's,  which  can  be  carried  out  easily 
upon  any  existing  Hewitt  instrument,  enables  one 
to    secure    rebreathing,    but    would    be    greatly 
improved  by  substituting  for  the  existing  expira- 
tory valve  one  of  the  Teter  type,  by  the  use  of 
which  positive  pressure  could  be  obtained.     One 
of  us  used  a  Burns  in  France  for  some  months, 
and  w^as  very  pleased  with  it. 

The  Guy-Ross  Method. 

The  Guy-Ross  method  of  giving  gas  and  oxygen 
is  a  distinct  improvement  on  that  of  Hewitt .  The 
apparatus  is  designed  on  the  principle  that  a 
known  and  absolutely  definite  quantity  of  oxygen 


144  ANESTHESIA  IN  DENTAL  SURGERY 

is  blended  with  a  known  quantity  of  nitrous  oxide. 
The  method  is  simple  and  the  results  uniform. 
Rebreathing  is  allowed  to  a  definite  extent. 
The  essential  parts  of  the  apparatus  are  as  follows : 

A  three-bottle  gas-stand  with  an  upright  crutch 
having  two  loo-gallon  cylinders  of  nitrous  oxide 
and  one  30-gallon  cylinder  of  oxygen,  all  operated 
by  foot -keys.  There  is  a  2 -gallon  bag  with  a 
Y  tube  for  admission  of  the  nitrous  oxide  by  one 
limb  from  the  cylinders,  and  a  i -gallon  bag  into 
which  ox^'gen  is  admitted  by  the  other  limb  of 
the  Y. 

There  is  the  usual  three-way  stop-cock,  which 
should  be  provided  with  an  ethyl  chloride  attach- 
ment between  bag  and  face-piece.  In  the  con- 
tinuity of  the  tube  from  the  oxygen  bag  is  fixed 
a  rubber  pump  as  used  for  a  Higginson  syringe, 
which,  when  compressed  by  the  hand,  drawls  at 
each  expansion  a  known  quantity  of  oxygen  from 
the  I -gallon  oxygen  bag  and  drives  it  into  the 
nitrous  oxide  bag. 

The  cycle  of  administration  is  as  follows: 

1.  Nitrous  oxide  with  as  much  oxygen  as  is 
desired  (measured  with  accuracy  and  varied 
according  to  circumstances)  is  passed  into  the 
I -gallon  bag. 

2.  The  patient  rebreathes  the  mixture  for  as 
long  as   is  desirable.     As  the   oxygen   factor  is 


SEQUENCES  AND  COMBINATIONS      145 

consumed  by  the  patient  it  is  kept  up  by  gradual 
additions  from  the  pump. 

3.  In  a  period  which  varies,  but  which  averages 
about  two  minutes,  the  CO2  in  the  bag  rises  to 
10  or  even  12  per  cent.  At  this  point  the  valves 
are  put  in  action,  and  the  contents  of  the  bag 
expired  into  the  outer  air. 

4.  The  valves  are  again  thrown  out  of  action 
and  the  bag  refilled  with  an  appropriate  mixture 
of  the  gases. 

In  the  practical  conduct  of  a  case  we  first  fill 
the  gallon  oxygen  bag.  The  bulb  is  squeezed 
twice  to  secure  any  air  being  expelled  before  we 
turn  on  the  oxygen.  The  three-way  tap  is  put 
to  air,  and  the  NgO  bag  filled.  Careful  adjust- 
ment of  the  face-piece  is  now  called  for,  and  no 
leakage  of  air  must  be  allowed.  The  tap  is  turned 
full  on  to  '  No  valves'  at  the  end  of  expiration. 
Rebreathing  is  usually  allowed  for  fifteen  seconds, 
and  oxygen  then  pumped  in.  Each  squeeze  of 
the  bulbs  pumps  in  2  ounces  of  oxygen.  It  is 
advisable  to  increase  the  percentage  of  oxygen 
during  the  administration,  and  we  find  that  two 
compressions  give  ij  per  cent,  of  oxygen.  If  two 
compressions  are  given  every  ten  seconds,  at  the 
end  of  sixty  seconds  the  patient  will  be  receiving 
7i  per  cent,  of  oxygen.  If  two  compressions  are 
given  every  fifteen  seconds,  the  mixture  at  the 

lO 


146  AN.ESTHESIA  IN  DENTAL  SURGERY 

end  of  a  minute  will  be  5  per  cent,  of  oxygen. 
It  is  seldom  necessary  to  give  more  than  two  com- 
pressions in  ten  seconds,  and  seldom  wise  to  give 
less  than  two  in  every  fifteen  seconds. 

The  period  of  induction  seldom  exceeds  eighty 
seconds,  but  it  may  be  longer  in  special  cases, 
when  there  is  no  risk  in  continuing  the  mixture. 
No  cyanosis  should  be  allowed  to  appear,  but  if 
by  chance  it  threatens,  oxygen  should  at  once  be 
pushed. 

The  period  available  is  about  thirty  seconds  from 
the  removal  of  the  face-piece. 

It  is  just  here  that  Bellamy  Gardner  brought 
his  ripe  judgment  and  knowledge  to  bear  on  the 
subject,  and  devised  an  almost  perfect  anaesthesia, 
induced  and  maintained  by  the  nasal  method  con- 
tinuously. He  adapted  Hewitt's  principle  of 
giving  definite  percentages  of  oxygen  to  the  nasal 
apparatus  of  Coleman,  improved  by  Paterson  and 
Nash.  Nash's  improvement,  it  may  be  said  in 
passing,  consisted  in  improving  the  rather  un- 
adaptable nose-piece  of  Paterson's  first  apparatus, 
making  several  sizes  '  money-lenders  and  others  ' 
of  soft  flexible  copper,  and  also  fitting  an  expira- 
tory valve,  which  latter  was  a  great  advance. 
Gardner  arranged  that  the  tubes  from  this  led 
to  a  Hewitt's  gas  and  oxygen  mixing  chamber. 

His  rubber  bag  differs  from  Hewitt's,  being 


SEQUENCES  AND  COMBINATIONS    147 

adapted  from  one  devised  by  A.  G.  Levy,  with  the 
small  oxygen  bag  contained  inside  the  larger  NgO 
bag.  Such  an  arrangement  tends  to  the  equalizing 
of  the  pressure  of  the  gases,  if  it  does  not  entirely 
secure  it.  It  is  important  to  avoid  distending  the 
oxygen  bag  if  an  equal  pressure  is  to  be  maintained . 
Both  bags  are  connected  with  the  gas  and  oxygen 
cylinders  respectively  by  a  piece  of  concentric 
tubing.  By  reversing  the  '  valve  chimney  '  at 
the  proximal  end  of  the  nose-piece  the  expiratory 
valve  is  put  out  of  action,  so  that  rebrea thing  is 
allowed. 

Beginning  with  6  per  cent,  of  oxygen,  this 
element  in  the  mixture  is  slowly  increased  up  to 
15  per  cent.,  and  after  a  period  of  induction  of 
ninety  seconds  anaesthesia  is  usually  complete. 
The  outer  or  NgO  bag  should  be  replenished  from 
time  to  time,  and  kept  full,  but  not  allowed  to 
become  distended  any  more  than  the  one  which 
it  contains. 

The  special  mouth-cover  may  be  required 
during  the  period  of  induction  if  the  patient 
inspires  too  freely  through  the  mouth.  One 
gallon  of  oxygen  usually  suffices,  so  that  the 
replenishing  of  this  bag  is  usually  unnecessary, 
but  the  pressure  in  the  nitrous  oxide  bag  must 
be  kept  up  nd  in  some  cases  made  a  little  plus. 
The  oxygen,   of   course,  takes  the   place  of  the 


148    ANiESTHESIA  IN  DENTAL  SURGERY 

air  valve  with  which  we  regulate  the  colour  in 
continuous  nasal  NgO  anaesthesia,  and  by  care- 
fully regulating  the  supply  according  to  the 
patient's  requii-ements  a  practically  normal  colour 
may  be  maintained  throughout,  with  complete 
absence  of  stertor — merely  quiet  nasal  respira- 
tion being  noticed  usually.  The  pupils  become 
moderately  •  contracted,  with  a  sluggish  corneal 
reflex.  The  pulse  inclines  to  be  quicker  and 
satisfactory  in  volume  and  character  generally. 
If  the  nitrous  oxide  is  pushed  and  given  under 
any  plus  pressure  some  degree  of  stertor  ma}^  be 
noticed,  but  is  easily  avoided.  The  moment 
to-and-fro  nasal  breathing  is  established  the 
K,0  gas  should  be  diminished. 

Properly  used,  this  apparatus  provides  the 
most  perfect  type  of  anaesthesia  available  from 
nitrous  oxide,  with  an  extraordinary  degree  of 
safety,  and  almost  unlimited  period  for  operative 
procedure,  and  a  minimum  disturbance  of  the 
patient's  equilibrium  both  during  and  after  the 
ansesthesia. 

Sight-Feed  Machines. 

The  sight-feed  principle  could  be  introduced 
into  any  machine,  but  its  great  advantage  lies  in 
the  fact  that  by  it  we  secure  control  over  the 
pressure  of  each  gas,  and  therefore  of  the  richness 


SEQUENCES  AND  COMBINATIONS     149 

in  oxj^gen  of  the  mixture,  at  the  very  beginning, 

as  it  were,  and  that  the  remainder  of  the  apparatus 

may  therefore  be  of  the  simplest  possible  type. 

Indeed,  the  ordinary  three-way  tap,  face-piece, 

and  2-gallon  bag  (Fig.  10),  as  used  for  giving  gas 

unmixed   with   oxygen,    may   with   a   sight-feed 

fitted  to  each  cylinder  serve   admirably  for  gas 

and  oxygen.     The  sight-feed  consists  of  a  glass 

chamber  roofed  in  by  a  metal  plate  perforated  by 

three  pipes,  two  of  entry  and  one  of  exit.     Each 

gas  is  led  through  its  appropriate  pipe  into  the 

chamber,  which  is  filled  three-quarters  full  with 

water.     Each  pipe  is  perforated  at  the  sides,  and 

it  will   be  obvious   that   if  the  pressure  of  gas, 

whether  oxygen  or  nitrous  oxide,  be  great,  bubbles 

will  be  seen  escaping  from  the  side  of  supply  pipe 

right  down  to  the  bottom  of  the  water,  while  if 

the  pressure  be  reduced  bubbles  will  be  seen  only 

from  the  orifices  in  the  upper  part  of  the  tube. 

Upon  the  surface  of  the  water  the  two  gases  meet 

and  mix,  and  pass  from  the  chamber  by  the  third 

tube,    that   of   exit,   towards   the   patient.     The 

anaesthetist   trains  his  eye   to   judge,   from   the 

deepest  level  at  which  he  can  observe  bubbles 

from  each  of  the  tubes  of  entry,  at  what  pressure 

each  gas  is  escaping — that  is,  to  all  intents  and 

purposes,  how  much  of  each  gas  is  passing  from  the 

cylinders  into  the  inhaler  from  which  the  patient 


150  AN.^.STHESIA  IN  DENTAL  SURGERY 

is  breathing.  B}^  manipulation  of  the  taps  at  the 
cylinder  heads  he  can  secure  the  mixture  which 
he  desires.  It  is  to  our  mind  certain  that  this 
method  has  a  large  future  before  it,  particularly 
if  combined  with  an  instrument  fitted  with  an 
expiratory  valve  of  the  Teter  type,  with  its  power 
of  causing  positive  pressure. 

It  will  be  noticed  that  many  of  the  methods 
and  instruments  above  described  hail  from  the 
United  States,  and  we  have  here  the  greatest 
pleasure  in  rendering  our  hoipage  to  the  sterling 
work  done  in  gas-oxygen  by  American  ansesthe- 
tists,  and  to  the  great  advances  they  have  made  in 
the  older  methods.  But  we  must  not  omit  to 
mention  that  several  British  makers,  notably 
Messrs.  Claudius  Ash  and  Co.,  have  introduced 
models  embod3dng  the  most  valuable  of  the  recent 
advances. 

Having  taken  our  reader  thiough  this  brief 
survey  of  possible  methods  and  appliances,  we  may 
now  ask  him  to  turn  to  the  practical  qitrcstion  of  the 
pur-pose  for  which  he  requires  a  gas-oxygen  appa- 
ratus. Upon  the  answer  to  that  question  will 
largely  depend  his  choice  of  individual  instrument. 

If  he  desires  it  to  meet  the  requirements  of 
extraction  work  only,  and  if  he  intends  to  adopt 
the  principle  of  the  single  dose,  doing  as  much 
under  that  dose  as  is  possible  and  readministering 


SEQUENCES  AND  COMBINATIONS    151 

upon  a  later  occasion  if  necessary,  then  the  Guy- 
Ross  method  has  much  to  recommend  it.  If, 
however,  he  desires  to  use  nasal  methods,  and  to 
essay  the  practice  of  analgesia,  then  he  must 
select  either  a  Teter,  a  Clarke,  or  one  of  the  similar 
instruments  made  by  British  firms  such  as  Ash 
and  Co.  All  these  are,  however,  immobile. 
For  a  machine  intended  for  frequent  transporta- 
tion Bellamy  Gardner's  apparatus  (see  p.  140) 
will  be  the  most  suitable  choice. 

Nitrous  Oxide  and  Ethyl  Chloride  in 
Sequence. 

This  combination  has  several  advantages, 
chief  amongst  which  is  the  fact  that  after-sickness 
is  less  frequent  than  after  ethyl  chloride  alone, 
only  occurring  in  about  5  per  cent,  of  the  cases. 
Further,  many  patients  prefer  to  lose  consciousness 
by  means  of  gas,  the  odour  being  less  perceptible 
and  more  pleasant  than  that  of  ethyl  chloride. 
Guy's  apparatus  described  under  Ethyl  Chloride 
does  very  well  for  the  administration,  and  we 
must  confess  a  liking  for  that  devised  by  the  late 
Sir  F.  W.  Hewitt,  which  consists  of  a  2 -gallon 
gas-bag  with  two  entrant  tubes  at  the  low^er 
extremity,  one  for  the  gas  and  the  other  for 
attaching  a  phial  of  ethyl  chloride. 

In  Guy's  apparatus  the  NgO  is  admitted  by 


152    ANESTHESIA  IN  DENTAL  SURGERY 

the  feed-tube  attached  to  the  angle-mount  by  a 
ball-and-socket  joint.  In  the  perpendicular  part 
of  the  three-way  tap  there  is  a  hole  marked  with 


FIG.    17. guy's  ethyl  chloride  INHALER. 

an  arrow,  and  when  this  corresponds  with  the 
pointer  in  the  bag-mount  the  holes  in  the  latter 
are  in  exact  register. 


SEQUENCES  AND  COMBINATIONS     153 

In  using  the  apparatus,  the  tap  is  turned  to 
'  Air.'  Gas  is  let  into  the  bag  until  it  is  full, 
and  the  bag-mount  is  turned  around  a  quarter  of 
a  circle  to  close  the  outlet.  The  gas-supply  is  now 
disconnected.  The  ethyl  chloride  tube,  kept  in 
the  dependent  position,  is  now  attached  to  the 
feed-tube. 

The  patient  may  be  seated  or  tying  down, 
but,  generally  speaking,  in  dental  work  the  sit  ting- 
up  posture  is  preferable,  being  more  convenient 
to  the  operator.  The  patient's  legs  should  be 
extended,  with  the  hands  resting  on  the  lap. 
The  anaesthetist  should  grasp  the  face-piece 
firmly  in  his  right  hand,  standing  on  the  left  side 
of  the  patient,  and  passing  his  arm  around  the 
patient's  neck  and  the  head-piece  of  the  chair. 
The  face-piece  must  be  carefully  and  firmly 
adjusted  to  the  patient's  face,  and  at  the  end  of 
an  expiration  the  tap  is  turned  to  'No  valves.' 
After  six  complete  respirations  the  ethyl  chloride 
supply-tube  is  tilted  up  and  the  drug  poured  into 
the  bag. 

The  patient  is  then  allowed  to  breathe  the 
mixture  for  from  twenty-five  to  thirty  seconds,  and 
should  then  be  ready  for  the  operation  to  begin. 
Time  spent  in  holding  the  breath  by  nervous 
patients,  or  those  who  find  the  smell  unpleasantly 
pungent,     must    not    be    counted.     During    the 


154   AN.ESTHESIA  IN  DENTAL  SURGERY 

twenty-five  seconds  mentioned  the  patient  should 
be  actively  breathing.  The  amount  of  ethyl 
chloride  introduced  into  the  bag  should  never 
exceed  5  c.c,  and  rarely  be  more  than  3  c.c.  For 
the  very  larg^  majority  of  cases  this  will  be  suffi- 
cient. It  is  important  that  the  bag  is  dry,  and 
that  the  temperature  of  the  operating-room  is 
not  below  60°  F. 

This  mixture  is  a  single-dose  anaesthetic,  and 
should  not  be  repeated  at  a  sitting,  or  sickness 
is  certain  to  result. 

The  Administration  of  Ethyl  Chloride  and 
Ether  in  Sequence. 

This  sequence  is  a  very  useful  one  in  dental 
surgery  for  cases  where  there  are  more  than  six 
teeth  to  extract,  or  where  there  are  a  number  of 
roots  to  remove  over  which  some  amount  of  diffi- 
culty is  anticipated.  The  time  afforded  will,  of 
course,  almost  entirely  depend  on  the  period  for 
which  the  patient  is  made  to  inhale  the  ether.  It 
is  easy  to  obtain  an  anaesthesia  of  from  two  and  a 
half  to  ten  minutes  by  means  of  this  method 
without  having  to  reapply  the  face-piece.  The 
chief  advantage  which  this  combination  possesses 
over  gas  and  ether  is  the  greater  portability  of 
ethyl  chloride  compared  with  nitrous  oxide  gas. 
The    apparatus    itself   is,    of   course,    much    less 


SEQUENCES  AND  COMBINATIONS    155 

bulky  also,  simply  consisting  of  a  Clover's  in- 
haler, with  the  slight  modification  already  de- 
scribed for  introducing  the  ethyl  chloride. 

This  sequence  is  somewhat  easier  to  give  than 
'  gas  and  ether  ' ;  but  in  deciding  between  the 
two  methods  it  must  be  remembered  that  '  gas,' 
being  tasteless,  is  more  agreeable  to  the  patient 
as  the  first  member  of  a  sequence  than  the  rather 
sickly  smelling  ethyl  chloride,  and  that  '  gas 
and  ether  '  holds  a  long  and  unrivalled  record 
for  almost  absolute  immunity  from  fatalities. 

The  dose  of  ethyl  chloride  is  introduced  into 
the  bag  just  before  the  administration,  and  need 
rarely  exceed  3 J  c.c,  and  i  ounce  of  ether  is 
introduced  into  the  ether  chamber.  If  the 
patient  shows  signs  of  recovery  from  the  ethyl 
chloride  before  the  ether  has  exerted  its  action, 
a  further  2  c.c.  of  ethyl  chloride  may  be  sprayed 
in.  This  will  only  be  required  in  the  case  of 
strong  or  alcoholic  men. 

In  conducting  the  administration,  the  patient 
should  be  allowed  to  take  six  or  eight  breaths 
of  the  ethyl  chloride,  and  then  the  ether  should 
be  turned  slowly  on.  The  administration  should 
be  carried  to  the  point  of  the  abolition  of  the 
corneal  reflex  and  moderate  dilatation  of  the 
pupils;  but  in  cases  where  a  long  anaesthesia  is 
desired  the  ether  may  be  pushed  without  fear. 


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Cti 


158    ANAESTHESIA  IN  DENTAL  SURGERY 

and  a  well-dilated  pupil  with   deep  anaesthesia 
be  established  before  the  face-piece  is  withdrawn. 

Nitrous  Oxide,  Oxygen,  and  Ethyl  Chloride 

Sequence. 

This  method  has  been  devised  by  Mr.  Guy  and 
one  of  ourselves  for  use  in  cases  where  the  period 
available  in  gas  and  oxygen  anaesthesia  is  not 
sufficiently  great,  and  where  the  anaesthetic  is 
given,  not  by  a  skilled  anaesthetist,  but  someone 
with  less  wide  experience,  such  as  a  dental  prac- 
titioner or  a  dental  surgeon.  It  is  simply  an 
amplification  of  the  NgO  and  oxygen  method 
described  on  pp.  143  and  219. 

Ethyl  chloride  is  used  as  an  adjuvant  to  the 
gas  and  oxygen.  The  apparatus  is  identical 
with  that  described  under  Gas  and  Oxygen,  but 
has  Guy's  ethyl  chloride  attachment  to  the  stop- 
cock. 

Previous  to  the  adjustment  of  the  face-piece, 
the  gas  and  3  c.c.  of  ethyl  chloride  are  introduced 
into  the  bag  and  the  ethyl  chloride  attachment 
respectively.  After  five  or  six  respirations  or 
rebreathings,  the  patient  having  been  warned 
not  to  mind  the  smeU,  the  ethyl  chloride  is  in- 
troduced into  the  gas-bag  in  the  usual  way. 
Oxygen  is  added  as  indicated  by  the  colour  of 
the    patient's    face.     The    induction   of   narcosis 


SEQUENCES  AND  COMBINATIONS    159 

is  more  rapid  when  the  mixture  of  gases  and 
ethyl  chloride  is  rebreathed,  the  average  time 
being  sixty  to  seventy  seconds.  Guy  bases  the 
undoubted  success  of  this  method  on  the  fact 
that  the  minimal  combination  of  two  drugs  of 
different  kinds  is  very  much  less  than  the  minimal 
narcotic  dose  of  the  same  two  drugs. 

On  this  principle,  if  the  time  available  by  this 
method  be  insufficient,  3  c.c.  of  ether  can  be 
added,  and  this  at  once  delays  the  evaporation 
of  the  ethyl  chloride  and  prolongs  the  anaesthesia. 
This  is,  of  course,  merely  an  alternative  to  rapidly 
introducing  the  Clover  chamber  between  face- 
piece  and  gas-bag. 

Guy  has  found  this  combination  of  gases  and 
ethyl  chloride  of  the  greatest  value  in  hospital 
practice,  and  highly  economical.  Quite  un- 
favourable types  of  patients  can  be  anaesthetized 
rapidly  and  with  complete  certainty,  including 
'  strong  athletic  males,  soldiers,  navvies,  and 
alcoholics  ' — the  last  of  both  sexes. 

Very  small  doses  of  ethyl  chloride  are  required 
for  children.  One  c.c.  is  enough  for  a  child  of 
three  to  four  years  old,  and  2  c.c.  for  one  of  ten 
or  thereabouts.  Oxygen  should  be  introduced 
almost  from  the  start,  and  the  ethyl  chloride 
introduced  in  from  ten  to  fifteen  seconds. 


i6o    ANAESTHESIA  IN  DENTAL  SURGERY 

Gas  and  Ether  Administration. 

The  apparatus  required  is  as  follows: 

A  Clover's  portable  inhaler,  with  a  good 
medium-sized  Earth's  face-piece  and  a  3-gallon 
gas-bag  fitted  with  an  ordinary  three-way  stop- 
cock; 4  or  5  feet  of  J-inch  stout  rubber  tubing 
joining  the  lower  end  of  the  gas-bag  to  the  nozzle 
of  a  two-bottle  (angle  pattern)  gas-stand  fitted 
with  pedal  keys. 

It  is  convenient  to  have  a  small  vulcanite  tap 
between  the  tubing  and  the  gas-bag,  so  that,  if  it 
is  desirable,  the  bag  may  be  filled  with  nitrous 
oxide  and  detached.  For  general  purposes  50- 
gallon  gas-bottles  will  be  found  most  convenient, 
and  it  is  well  to  have  three  or  four  in  stock,  so 
that  an  empty  one  can  at  once  be  replaced.  In 
turning  on  the  gas,  always  use  the  same  bottle — 
the  right  or  left — until  it  is  exhausted,  and  so 
avoid  the  possibility  of  the  two  running  out  at 
the  same  time. 

A  filler  is  always  provided  with  a  Clover's 
inhaler,  which  just  contains  ij  ounces;  person- 
ally, I  never  use  this,  but  find  it  more  convenient 
to  keep  a  supply  of  ether  in  a  corked  medicine 
bottle,  from  which  it  is  easy  to  measure  off  about 
I J  ounces  (three  tablespoonfuls),  and  then  '  jump- 
ing '  of  the  stopper,  which  so  often  is  a  nuisance 
in  a  warm  room,  is  avoided.     When  filling  the 


SEQUENCES  AND  COMBINATIONS    i6i 


FIG.    1 8. — GAS    AND    ETHER   APPARATUS. 


ether-chamber,  always  turn  the  index  on  a  httle 
to  '  2  '  or  '  3,'  as  otherwise  the  ether  bubbles  back 
and  is  wasted. 


II 


i62    AN.ESTHESIA  IN  DENTAL  SURGERY 

The  figures  o,  i,  2,  3,  and  F  (full),  marked  on 
the  cylindrical  portion  of  the  chamber,  have  the 
following  significance,  as  indicating  the  pro- 
portion of  the  air  respired  which  is  passing  into 
the  ether-chamber.  When  the  indicator  stands 
at  *  o,'  it  signifies  that  the  patient  is  breathing  to 
and  from  the  bag — that  is,  either  pure  air  or 
nitrous  oxide — and  that  none  of  the  air  which  is 
passing  backwards  and  forwards  from  the  patient's 
mouth  to  the  bag  is  being  allowed  to  traverse 
the  interior  of  the  ether-chamber  on  its  way. 

With  the  indicator  at '  i,'  one  part  in  every  four 
is  circulating  over  the  ether,  while  the  other  three 
parts  are  circulating  backwards  and  forwards  as 
before.  With  the  indicator  at  *  2,'  two-fourths, 
or  one-half,  are  entering  the  ether-chamber;  at 
*  3  '  three-fourths ;  and  at  '  F,'  or  full,  all  the 
breath  is  passing  into  the  ether-chamber  on  its 
way  to  and  from  the  bag. 

The  Barth  three-way  tap  is  similar  to  that  used 
for  ordinary  gas  administration,  the  structure  of 
which  is  explained  on  p.  54.  When  filling  the 
bag,  the  tap  is  set  at  '  Air  ' ;  at  the  start  of  the 
inhalation  and  for  about  six  breaths  at  *  Valves,' 
and  then  it  is  pushed  on  to  *  No  valves.'  By  that 
time  the  bag  will  be  about  half  empty,  and  should 
be  partially  recharged  with  nitrous  oxide. 

Guy's  practice  is  to  turn  the  tap  to  '  No  valves  ' 


SEQUENCES  AND  COMBINATIONS    163 

from  the  start;  this  is  contrary  to  Hewitt's 
custom,  with  which  the  author  is  inclined  to  agree. 
By  allowing  the  patient  six  or  seven  breaths 
through  the  valves,  a  large  amount  of  air  and 
carbonized  air  is  got  rid  of,  which  would,  so  to 
speak,  dilute  or  adulterate  the  nitrous  oxide  if 
expired  into  the  bag,  and  make  the  anaesthesia 
produced  more  of  an  asphyxial  type  than  a  pure 
nitrous  oxide  narcosis,  and  headache  and  nausea 
more  common  sequeL^.  By  getting  rid  of  the 
tidal  and  residual  air,  etc.,  one  rapidly  gets 
the  patient  under  the  influence  of  the  gas.  On  the 
other  hand,  later  on  in  the  induction  of  anaesthesia 
there  is  no  objection,  but  quite  the  contrary,  to 
turning  back  the  index  to  '  Air,'  thus  giving  the 
patient  a  breath  of  air  to  lessen  cyanosis,  and 
this  will  to  no  appreciable  extent  shorten  the 
period  of  available  anaesthesia. 

Simultaneously  with  the  setting  of  the  tap  at 
'  No  valves  '  the  ether  vapour  may  be  turned 
on.  This  will  generally  be  found  to  be  about 
twenty-five  seconds  from  the  start.  The  rotation 
of  the  chamber  is  begun  very  slowly,  and  if  the 
patient  shows  no  sign  of  choking  or  resenting, 
the  vapour  is  continued  more  boldly  until  the 
indicator  stands  at  '  4  '  and  '  F.'  If  coughing  or 
holding  of  the  breath  occurs,  at  once  switch  the 
chamber  back;  *  Reculez  pour  le  mieux  sauter,' 


164    AN.^STHESIA  IX  DENTAL  SURGERY 

and,  on  regular  breathing  being  re-established, 
increase  the  rotation.  Never  force  the  ether 
vapour  and  so  cause  respiratory  hesitancy,  which 
will  interfere  with  the  production  of  a  good,  quiet 
anaesthesia,  for  the  dulling  of  the  patient's  cough 
reflex,  etc.,  with  the  nitrous  oxide  is  merely  a 
question  of  time. 

Some  degree  of  lividity  is  usually  associated 
with  the  establishment  of  deep  anaesthesia,  unless 
a  good  deal  of  time  has  been  taken  over  the 
induction  and  air  freely  admitted.  In  dealing 
with  ordinary  healthy  patients,  and  as  a  matter 
of  routine,  however,  the  administrator  can  safely 
disregard  this  until  it  is  at  all  marked  or  associated 
with  stertor,  when  the  tap  should  be  at  once 
turned  to  '  Air  '  and  two  or  three  respirations 
allowed,  which  will  cause  the  prompt  disap- 
pearance of  the  cyanosis. 

Of  course,  where  the  patient  is  not  robust,  is 
anaemic,  or  suffering  from  any  cardiac  trouble, 
especially  '  strained  '  or  muscularly  feeble  heart, 
more  care  than  usual  is  needed.  Anaemic  patients 
have  a  marked  tendency  to  become  rapidly 
cyanosed,  and  then  stertor,  rigidity,  and  opis- 
thotonos ensue,  necessitating  the  withdrawal  of 
the  anaesthetic,  possibly  the  use  of  a  mouth  wedge, 
but  at  any  rate  a  liberal  allowance  of  air. 

The  establishment  of  anaesthesia  may  be  recog- 


SEQUENCES  AND  COMBINATIONS     165 

nized  from  the  loss  of  conjunctival  reflex  (the 
patient  does  not  *  wink '  when  his  eyeball  is 
touched),  from  regular  automatic  breathing,  a 
more  or  less  dilated  pupil  and  muscular  fiaccidity, 
the  arm  dropping  limply  at  the  patient's  side  if 
raised  and  let  go.  Very  robust  men,  alcoholics, 
and  hysterical  or  neurotic  females  are  not  usually 
good  subjects  for  gas  and  ether,  for  they  some- 
times get  excited  when  half  '  over,'  and  struggle 
violently  or  shout  and  scream.  With  a  little  care, 
however,  these  demonstrations  may  be  avoided 
by  anticipating  them,  and  getting  the  patient 
more  fully  under  the  gas  before  turning  on  ether. 

It  is  of  extreme  importance  to  see  that  no 
leakage  of  air  occurs  throughout  the  administra- 
tion from  the  apparatus  being  out  of  order  and 
leaking,  or  from  a  badly -adjusted  face -piece. 
The  uncontrolled  admission  of  air  in  this  way 
invariably  prolongs  the  period  required  to  induce 
anaesthesia,  and  frequently  causes  struggling  and 
excitement. 

It  is  well  to  bear  in  mind  that  both  before  and 
after  the  extractions  have  begun  the  patient  may 
utter  sounds  and  perform  co-ordinated  move- 
ments, although  unconsciousness  and  analgesia  are 
perfectly  maintained,  and  if  there  are  friends  in 
the  operating-room,  or  near,  it  will  be  wise,  in 
some  cases,  to  explain  this. 


t66  AN.ESTHESIA  IN  DENTAL  SURGERY 

The  duration  of  the  ancBsthesia  is  an  entirely 
variable  quantity,  and  will  depend  on  the  dura- 
tion of  the  administration,  the  amount  of  ether 


FIG.    19.— GUY  S   ARRANGEMENT    FOR    ADMINISTERING 
GAS    AND    ETHER. 

inhaled,  and  the  type  and  constitution  of  the 
patient. 

If  the  administration  be  properly  conducted. 


SEQUENCES  AND  COMBINATIONS   167 

and  one  minute  and  a  quarter  to  one  minute  and  a 
half  be  allowed  to  elapse  from  the  moment  of  the 
adaptation  of  the  face-piece,  an  anaesthesia  of  at 
least  a  minute  should  be  available,  allowing  suffi- 
cient time  for  a  moderately  expert  dentist  to 
extract  a  couple  of  difficult  teeth  or  six  or  seven 
easy   ones.     It    is    always    well   to    leave   some 
margin,  however,   and  the   '  gas  and  ether  se- 
quence '   may  be   administered   for  two,   three, 
four,  five,  or  ten  minutes,  according  to  the  time 
which  it  is  expected  the  extractions  will  take  to 
effect.     Of  course,  when  the  ether  is  pushed  in  this 
way,  the  patient  passes  into  a  condition  of  deep 
anaesthesia,   and   the   responsibility   of  the   case 
becomes  so  much  the  greater.     The  pupils  dilate 
up  and  become  fixed — that  is,  do  not  contract  on 
raising  the  eyelid ;  the  breathing  is  deep,  regular, 
and    somewhat    stertorous;    the    patient's    face 
flushes,  and  free  perspiration  is  sometimes  seen. 
The  patient  is  '  charged  up  '  with  a  large  dose  of 
ether,  just  as  he  would  be  with  a  large  dose   of 
alcohol,  and  while  there  is  really  little  more  risk 
as  regards  his  condition  in  the  former  than  in  the 
latter  case,  still,  in  view  of  the  prolonged  period 
of  complete  unconsciousness  and  the  Viature  of 
the  operative  procedure,  involving  free  haemor- 
rhage and  possibly  some  obstruction  in  the  air- 
way, the  administrator  requires  to  have  his  wits 


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in 

I/O  ANAESTHESIA  IN  DENTAL  SURGERY 

about  him.  When  patients  require  extractions 
which  will  necessitate  the  maintenance  of  com- 
plete analgesia  and  unconsciousness  for  any  period 
over  two  minutes,  it  is  strongly  advisable  to  have 
in  a  fuUy-qualified  expert  at  anaesthetic  work  to 
assist,  and  take  full  charge  of  the  anaesthetic. 

Guy,  for  routine  work,  a  vocates  the  adminis- 
tration of  gas  and  ether  just  up  to  the  stage  of 
disappearance  of  the  conjunctival  reflex,  so  as 
to  produce  one  and  a  half  to  two  minutes  of 
anaesthesia,  and  his  teaching  is  to  extract  rapidly 
and  do  as  much  as  possible  in  the  time  available, 
but  if  unable  to  complete  the  operation,  simply 
get  the  patient  back  another  day.  Of  course, 
when  the  patient  lives  near  at  hand,  and  especially 
when  dealing  with  hospital  patients,  this  will 
answer  well;  but,  then,  there  are  patients  coming 
from  a  distance  to  be  considered,  and  there  are 
many  people  who  do  not  like  to  undergo  the 
dreaded  ordeal  of  anaesthesia  twice,  or  who,  in 
colloquial  language,  desire  the  dentist  to  '  make  a 
job  of  it  '  at  the  sitting  !  While  there  is  a  distinct 
advantage  in  only  giving  such  an  amount  of  ether 
as  will  not  incapacitate  the  patient  from  going 
back  to  his  occupation  in  three  or  four  hours, 
the  wishes  of  such  patients  can  be  readily  met 
and  at  the  same  time  the  most  difficult  assort- 
ment  of  teeth  stumps    and  roots — even   '  lower 


SEQUENCES  AND  COMBINATIONS     171 

wisdoms  ' — may   be   extracted    tuto    et  jucunde, 
with  one  full  inhalation  of  ether. 

We  have  personalty  sometimes  afforded  the 
operator  fifteen  minutes,  during  which  thirty- 
two  teeth,  entire  or  fragmentary,  have  been 
removed.  Guy  has  expressed  the  opinion  that 
a  reasonably  expert  dentist  should  be  able 
'  to  clear  a  mouth  '  in  four  minutes.  Of  course 
some  extractions  are  very  easy  and  some  very 
much  the  reverse,  according  to  the  number  of 
teeth  and  the. manner  of  their  setting;  but  usually 
all  that  is  needed  can  be  done  in  ten  minutes  at 
the  very  outside,  and  the  consumption  of  more 
time  is  undesirable  and  due  to  a  bungling  operator. 
Mr.  Guy  has  sent  out  from  the  Edinburgh  Dental 
School  hundreds  of  dental  surgeons  who,  by  a 
special  system  of  training  which  he  has  made 
peculiarly  his  own,  are  quick  and  expert  operators, 
and  in  this,  if  for  no  other  reason,  he  has  earned 
the  appreciation  and  gratitude  of  more  than  one 
anaesthetist. 


CHAPTER  VIII 

THE  USE  OF  LOCAL  ANESTHESIA 

At  the  present  day  a  work  of  this  character  could 
not  be  considered  complete  without  the  use  of 
local  anaesthetics  in  dental  surgery  being  con- 
sidered pretty  fully.  For  the  last  fifteen  years 
this  method  has  been  in  considerable  favour  for 
use  in  the  extraction  of  one  or  more  teeth — 
sometimes  where  quite  a  number  are  being  ex- 
tracted; we  think  with  doubtful  wisdom  in  such 
cases. 

The  tendency  to  use  local  aucesthetics  has, 
indeed,  at  times  been  overdone  both  in  dental 
and  general  surgery.  Much  literature  on  the 
subject  has  emanated  from  Paris,  and  the  practice 
has  at  all  times  been  more  popular  on  the  Con- 
tinent than  in  this  country. 

Sauvez,  of  L'Ecole  Dentaire,  Paris,  has  given 
the  subject  very  great  attention,  and  read 
a  paper  in  1908  at  the  International  Congress  of 
Dental  Surgery  at  St.  Louis,  but  he  did  not  meet 
with    an   entirely    encouraging   reception.     This 

172 


THE  USE  OF  LOCAL  ANAESTHESIA     173 

was  in  many  ways  to  be  expected  in'the  land  where 
general  anaesthesia  had  its  birth;  but,  apart  from 
this,  there  seems  no  manner  of  doubt  that  Ameri- 
cans are  by  temperament  in  no  way  likely  to  be 
good  subjects  for  local  anaesthetics,  and  the  same 
may  be  said  of  the  large  majoritj^  of  the  Anglo- 
Saxon  race. 

Best  of  all  suited  for  local  anaesthetics  are 
the  stolid,  phlegmatic  persons  of  any  nationality 
and  French  hospital  patients,  with  whom  the 
repeated  assurances  of  the  surgeon  concerned 
that  they  will  feel  '  no  pain  '  cannot  be  altogether 
without  influence. 

In  our  own  country  there  are  many  tj^pes  of 
patients  for  whom  local  anaesthesia  is  not  to  be 
recommended.  Young  children,  particularly  if 
they  are  by  temperament  nervous  and  excitable, 
are  bad  subjects  for  it  at  all  times.  Neurotic, 
hysterical  women  it  is  also  quite  hopeless  to  deal 
with  in  this  way,  unless  on  their  own  urgent  request 
and  insistence,  when  on  occasion,  whatever  they 
actually  have  felt,  they  will  assert  that  the  opera- 
tion has  '  not  hurt  them  in  the  very  least,  and 
that  they  were  quite  right  to  choose  cocaine  !' 
There  are  certain  individuals  who  have  a  rooted 
objection  to  losing  consciousness  of  their  surround- 
ings and  giving  themselves  up  to  a  general  anaes- 
thetic.   For  these,  if  there  be  no  contra-indication, 


174    AN.^STHESIA  IN  DENTAL  SURGERY 

and  if  there  be  good  chance  of  the  analgesia  being 
reasonably  eihcient,  a  local  anaesthetic  is  to  some 
extent  indicated.  Further,  there  are  other  people 
who  can  never  be  thoroughly  rendered  anaesthetic 
by  means  of  nitrous  oxide,  although  they  are  rare, 
and  if  the  extraction  required  be  a  simple  one, 
local  anaesthesia  may  be  often  used  with  advan- 
tage. There  is  scarcely  a  dental  surgeon  in  prac- 
tice who  has  not  at  one  time  or  another  been  an 
enthusiastic  advocate  of  local  anaesthesia  (which 
has  invariably  meant  cocaine  under  its  own  or 
a  proprietary  name),  but  there  are  few  who  remain 
so  for  longer  than  a  year  or  two.  Doubtless 
there  are  fashions  in  dentistry  and  anaesthetics, 
as  in  other  things,  but  failures  to  produce  a 
satisfactory  degree  of  analgesia,  bad  after-effects, 
such  as  tendency  to  syncope  (which  may  come  on 
after  the  patient  has  left  the  house),  or  sloughing 
of  the  gum  in  one  or  two  cases,  tend  to  restrict 
the  use  of  cocaine  and  preparations  containing  it. 
The  general  tendency  at  the  present  day  seems  to 
be  to  use  a  solution  of  i  per  cent,  strength, 
and  this  is  what  Sauvez  himself  employs.  He 
(though  a  cocaine  enthusiast)  lays  it  down  as  a 
rule,  however,  that  if  more  than  a  cubic  centimetre 
(i6  mins.  approx.,  such  as  an  ordinary  hypodermic 
syringe  holds)  even  of  this  weak  solution  be  used,  the 
patient  should   be   placed  in  the  supine  position, 


THE  USE  OF  LOCAL  ANAESTHESIA     175 

and  should  remain  resting  for  a  considerable  time 
after  the  operation  is  completed. 

Such  precautions  are  by  no  means  common 
among  dental  surgeons  who  use  cocaine  in  this 
country,  and  this  may  account  to  some  extent 
for  the  frequency  of  syncopic  attacks  in  patients 
who  have  been  treated  with  cocaine.  The  advo- 
cates of  local  anaesthesia  are  wont  to  minimize 
the  risk  of  cocaine,  while  they  exaggerate  the 
dangers  and  disadvantages  of  general  anaesthesia, 
more  often  from  ignorance  than  not.  Each  has 
its  place,  doubtless,  in  general  and  dental  surgery. 
There  have  been  authorities  who  were  as  strenuous 
opponents  of  cocaine  as  others  were  advocates 
of  it,  and  there  is  much  to  be  said  on  both 
sides. 


The  Advantages  of  General  Anaesthesia. 

1.  The  anaesthesia  is. certain  and  can  be  guaran- 
teed, while  with  local  analgesics  we  can  only  say, 
at  the  best,  it  is  almost  certain. 

2.  The  patient  does  not  realize  the  effort  which 
the  operator  puts  forth  on  his  jaw,  nor  feel  the 
jar  of  the  forceps. 

3.  Several  different  extractions  can  be  carried 
out  at  the  same  time. 

4.  Certain  authors    say   that    the   healing    is 


176     ANAESTHESIA  IN  DENTAL  SURGERY 

more  rapid  than  when  a  local  anaesthetic  is 
employed,  and  we  believe  this  to  be  generally 
the  case. 

Advantages  of  Local  Anaesthesia. 

1.  The  lower  rate  of  mortality  is  one  which 
cannot  be  gainsaid,  if  ordinary  precautions  be 
taken  to  see  that  not  too  strong  solutions  of 
cocaine  are  employed. 

2.  There  is  no  need  for  any  assistants  (or 
witnesses  in  the  case  of  female  patients) .  There 
is  no  need  to  hold  the  patient  down,  etc.,  for  there 
is  no  period  of  excitement  and  struggling. 

3.  The  analgesia  lasts  long  enough  to  prevent 
the  patient  feeling  the  after-pain  of  the  extraction 
to  a  great  extent,  although  in  some  cases  severe 
after-pain  may  be  experienced. 

4.  There  is  no  apparatus  of  a  complicated  nature 
to  get  ready,  for  the  syringe  is  always  ready,  if 
only  used  once  in  10,000  cases. 

The  two  methods  commonly  employed  to  pro- 
duce analgesia  by  local  treatment  are : 

1.  By  the  injection  of  drugs  into  the  part. 

2.  By  means  of  local  application  of  very  vola- 
tile substances  to  produce  freezing  of  the  part. 


THE  USE  OF  LOCAL  AN^ESTHESLA.     177 

The  Production  of  Local  Anaesthesia  by 
THE  Injection  of  Drugs. 

The  drugs  most  commonly  used  for  the  purpose 
at  the  present  day  are,  in  order  of  popularity, 
•cocaine,  eucaine,  tropa-cocaine,  acoine,*stovaine,' 
closely  allied  to  cocaine,  and  novocain. 

With  any  of  these  drugs  (with  the  exception  of 
stovaine)  suprarenal  extract  may  be  employed 
to  intensify  and  localize  the  action.  By  far  the 
most  largely  used  drug  for  local  anaesthesia  is 
cocaine.  It  spurted  into  fame  at  the  moment  of 
its  discovery,  and  as  rapidly  got  into  disrepute. 
Again  it  got  popular  when  it  was  found  that 
accidents  were  uncommon,  comparatively  speak- 
ing, if  weak  solutions  were  employed  and  precau- 
tions taken.  Periodically,  new  synthetic  drugs 
have  been  placed  on  the  market,  and  vaunted  as 
having  all  the  advantages  of  cocaine  without  its 
disadvantages,  but  each  in  turn  has  proved  in- 
ferior, and  at  the  present  day,  with  its  drawbacks 
fully  known  as  they  now  are,  cocaine  undoubtedly 
holds  the  field  as  the  best  local  anaesthetic  we 
have.  It  seems  likely  that  stovaine  will  go  nearer 
to  displacing  it  from  its  proud  position  than 
any  other  synthetic  compound,  but  the  clinical 
evidence  at  our  disposal  at  the  present  moment 
is  not  sufficiently  ample  to  enable  us  to  speak 

definitely  on  this  point. 

12 


lyS   AN.ESTHESIA  IN  DENTAL  SURGERY 

Cocaine  Hydrochlorate. — Cocaine  is  utilized 
for  anesthetic  purposes  chiefly  in  the  form  of  the 
hydrochlorate.  This  alkaloid  was  first  obtained 
from  the  leaves  of  Erythroxylon  Coca  by  Gaedeke 
in  the  year  i860.  It  was  first  employed  for 
surgical  work  by  Keller,  of  Vienna,  in  1884, 
and  since  that  time  has  been  of  priceless  value 
chiefly  in  ophthalmic  surgery. 

The  salt  is  freely  soluble  in  water,  spirit,  and 
glycerine.  Solutions  of  it  are  apt  to  become 
cloudy  from  the  growth  of  fungi,  and  to  prevent 
this  boric  or  saHcylic  acid  is  commonly  added  by 
chemists.  It  is  always  desirable,  as  far  as  pos- 
sible, only  to  use  freshly  prepared  solutions  if 
the  best  results  are  to  be  obtained,  and  these 
should  be  boiled  beforehand  to  render  them 
sterile. 

One  of  the  most  marked  properties  possessed  by 
cocaine,  apart  from  its  anaesthetic  properties,  is 
its  power  of  depressing  the  circulatory  organs. 
Faint ness  is  very  readily  induced  in  some  people, 
even  by  very  small  doses ;  they  become  extremely 
pale,  and  their  pulse  is  found  to  be  weak  and 
irregular,  and  even  imperceptible  at  the  wrist. 

Symptoms  pointing  to  the  absorption  of  cocaine 
into  the  general  circulation  most  commonly  arise 
when  the  injection  is  made  into  a  highly  vascular 
part,  or  the  needle  has  by  accident  punctured 


THE  USE  OF  LOCAL  ANiESTHESL\     179 

a  bloodvessel.     Untoward  symptoms  may  arise 
from  an  unnecessarily  large  dose,  impurities  in 
the  solution,  want  of  aseptic  precautions,  or  from 
physical  causes  apart  from  the  anaesthetic.     The 
effect  produced  by  any  given  dose,  however,  will 
vary  greatly  with  the  type  of  the  patient  on  whom 
it  is  employed,  the  age  of  the  patient,  and  the 
part  treated.     A  great  deal  depends  on  the  ab- 
sorptive capacity  of  the  mucous  membrane,  as 
influencing  the  actual  amount  of  cocaine  which 
gets  into  the  circulation.     The  laryngeal  mucous 
membrane  will  stand  a  strong  solution  of  10  per 
cent.,  or  even  15  per  cent.,  which  for  the  nasal 
mucous  membrane  or  urethra  would  be  much  too 
strong.     The  absorption  of  |  to  J  of  the  grain 
drug  will,  in  the  large  majority  of  patients,  do  no 
harm;    i    grain    will    often    produce    dangerous 
symptoms,  while,  on  the  other  hand,  we  have 
known    as   much    as    2  grains  injected  at  once 
produce  no  unpleasant  effect,  the  patient  being 
a  vigorous  man.     It  is  this  very  uncertainty  of 
action  as  regards  toxicity,  however,  that  makes 
cocaine  so  dangerous,  and  a  further  difficulty  is 
that  the  symptoms  may  be  delayed  for  a  consider- 
able time,  and  only  come  on  when  the  patient  is 
on  his  way  home. 

The   toxic    symptoms    are:    Trembling    in    the 
hmbs,    especially   the   lower   extremities;   head- 


i8o   ANESTHESIA  IN  DENTAL  SURGERY 

ache,  vertigo,  pallor;  a  cold,  moist  skin;  feeble, 
rapid  pulse,  which  in  grave  cases  becomes  imper- 
ceptible; slow,  shallow  respirations;  incoherence 
of  speech,  nausea,  vomiting,  unconsciousness, 
tremors,  and  other  muscular  spasms;  epilepti- 
form attacks,  dilated  and  unequal  pupils,  and 
disturbance  of  the  circulation,  ending  in  dyspnoea 
and  death  by  asphyxia. 

The  treatment  consists  in  using  every  effort 
to  stimulate  and  restore  the  circulation.  The 
patient,  if  not  already  supine,  should  be  immedi- 
ately placed  in  this  position,  air  freely  admitted 
and  some  alcoholic  stimulant  quickly  adminis- 
tered, or  a  drachm  of  ether  injected  subcutane- 
ously.  The  patient  should  be  warmly  covered, 
and  pulse  and  respiration  carefully  watched, 
artificial  respiration  being  employed  if  necessary. 
A  capsule  of  nitrite  of  amj'l  may  be  of  service, 
and  -YTs  grain  of  atropine  and  lo  minims  of 
tincture  of  strophanthus  may  be  injected  hypo- 
dermic ally. 

The  Use  of  Cocaine  combined  with  Adrenalin. 
— As  is  generally  known,  liq.  adrenalin  possesses 
a  strong  local  vaso-constrictor  power,  so  much  so 
that  even  after  a  simple  swabbing  with  a  solution 
of  I  :  1,000  it  is  possible  to  obtain  in  a  few  minutes 
a  local  ischsemia  such  that  operations  on  the  nasal 
cavities,  so  ready  to  bleed  as  a  rule,  have  been 


THE  USE  OF  LOCAL  AN^STHESL\     i8i 

performed  without  the  patient  losing  a  drop  of 
blood. 

The  advantage  of  using  this  substance  along 
with  cocaine  is  that,  in  addition  to  rendering  the 
region  to  be  anaesthetized  bloodless,  it  enhances 
the  local  action  of  the  cocaine  while  lessening 
constitutional  effects.  It  is  well  known  that 
cocaine  acts  harmfully  on  inflamed  and  congested 
tissues,  and  its  action,  when  injected  into  tissues 
that  are  soft  and  spongy,  is  often  unreliable.  In 
such  cases,  by  using  adrenalin  to  produce  tem- 
porary ischsemia,  we  obtain  the  best  results.  A 
suitable  solution  to  employ  is  one  of  i  per  cent, 
cocaine  with  5  per  cent,  adrenalin.  *  A  certain  dis- 
advantage may  be  urged  in  the  absence  of  bleeding 
after  a  tooth  is  extracted  under  this  combination, 
for  in  many  cases  the  slight  bleeding  which  under 
ordmary  conditions  follows  the  extraction  of  a 
tooth  may  be  considered  rather  an  advantage, 
tending  to  lessen  the  congestion  in  an  inflamed 
gum. 

The  following  advantages  may  be  claimed  for 
this  combination,  however : 

1.  The  gum  is  rendered  quite  blanched  by  the 
first  injection. 

2.  There  is  no  bleeding  from  the  prick  of  the 
needle. 

*  I  :  20,000. 


i82    ANAESTHESIA  IN  DENTAL  SURGERY 

3.  There  is  no  bleeding  after  the  tooth  is 
extracted,  even  in  haemophiUcs,  which  allows  of 
clean  operating  and  facilitates  the  removal  of 
difficult  roots. 

4.  Analgesia  is  practicable  even  in  soft  and 
inflamed  tissues,  and  more  durable  and  complete 
in  healthy  tissues. 

5.  There  are  no  syncopal  symptoms  nor  cerebral 
attacks  as  a  sequel,  but,  on  the  contrary,  the 
cardiac  systole  is  more  energetic,  and  tbe  heart- 
sounds  better  defined. 

In  view  both  of  the  costliness  and  high  toxicity 
of  cocaine,  from  time  to  time  attempts  have  been 
made  to  find  some  synthetic  drug  which  would 
be  a  good  substitute.  Chief  among  those  which 
have  been  introduced  are  tropa-cocaine  and 
^-eucaine.  These  are  very  similar  to  one  another 
and  to  cocaine. 

EucAiNE  has  been  extensively  used  in  the  place 
of  cocaine,  and  the  chief  advantages  claimed  for 
it  are  the  following : 

1.  It  has  only  one  -  fourth  the  toxicity  of 
cocaine. 

2.  Its  exhibition  is  followed  by  no  unpleasant 
or  dangerous  after-effect. 

3.  Its  action  is  more  constant  and  lasting  than 
that  of  cocaine. 

4.  It   does  not   decompose  on  boiling   (which 


THE  USE  OF  LOCAL  AN^STHESL\     183 

cocaine  sometimes  does  do),  and  so  can  be  ren- 
dered permanently  sterile  in  solution. 

5.  It  costs  only  one-half  of  the  price  of  cocaine. 

On  the  other  hand,  eucaine  is  much  less  soluble 
than  cocaine,  requiring  20  parts  of  cold  water  to 
dissolve  i  part  of  eucaine  and  10  parts  of  hot 
water.  It  is  considerably  more  irritating  to 
delicate  membranes  than  cocaine — e.g.,  the  con- 
junctiva. It  is  slower  in  action  than  cocaine,  and 
after  injecting  it  for  a  dental  extraction  it  is  neces- 
sary to  wait  at  least  ten  minutes  in  order  to  get  the 
full  analgesic  effect;  its  tendency  to  cause  irrita- 
tion leads  to  hyperaemia  of  the  tissues  frequently, 
which  may  be  embarrassing  to  the  operator;  but 
this  drawback  can,  of  course,  be  overcome  by 
combining  suprarenal  extract  with  it.  Further, 
some  observers  have  stated  that  eucaine  is  less 
intense  an  analgesic  than  cocaine,  and  that  the 
analgesia  produced  by  it  is  shorter  in  duration; 
but,  most  important  of  all,  they  state  that  it  is 
practically  as  dangerous  as  cocaine,  and  that  its 
toxicity  has  been  greatly  underrated. 

A  sterile  2  per  cent,  solution  may  he  prepared  as 
follows  :  To  I  part  of  ^-eucaine  49  parts  of  dis- 
tilled water  are  added.  Heat  the  mixture  in 
a  test-tube  over  a  spirit-lamp  until  solution  has 
taken  place :  then  heat  to  boiling-point,  covering 
the  mouth  oi  the  test-tube  with  a  piece  of  cotton- 


i84   ANAESTHESIA  IN  DENTAL  SURGERY 

wool.  A  thoroughly  sterile  solution  is  thus 
obtained. 

Dose. — 15  to  20  minims  of  a  2  per  cent,  solution 
is  sufficient  for  the  extraction  of  a  single  tooth. 

I^eclus  has  employed  eucaine  on  over  4,000 
occasions  without  any  serious  accident,  but 
Sauvez  regards  it  as  equally  dangerous  with 
cocaine,  and  considerably  inferior  in  analgesic 
power. 

Eucaine  may  be,  like  cocaine,  combined  with 
liq.  adrenalin.  '  Eudrenin,'  a  preparation  of 
Parke,  Davis  and  Co.,  is  of  this  nature,  and  is 
put  up  in  convenient  glass  capsules,  insuring 
sterility,  etc. 

Tropa-Cocaine. — Of  tropa-cocaine  most  of  the 
remarks  which  we  have  just  made  in  regard  to 
eucaine  seem  to  be  true.  Sauvez  considers  it  as 
inferior  to  cocaine,  and  equally  toxic  to  all  intents 
and  purposes.  Dorn  has,  however,  used  it  on 
hundreds  of  occasions  with  good  results.  In 
no  case  did  he  observe  the  slightest  toxic  symptom, 
and  neither  excitement,  dyspnoea,  nor  faintness 
was  experienced.  For  the  majority  of  cases  he 
used  a  3  to  4  per  cent,  solution,  injecting  from 
10  to  30  minims  in  three  to  five  punctures  in  the 
direction  of  the  roots  of  the  teeth.  The  analgesia 
obtained  by  means  of  it  lasts  about  ten  minutes. 

Stovaine  is  the  proprietary   name   of  chlor- 


THE  USE  OF  LOCAL  ANAESTHESIA     185 

hydrate  of  yS-amylene,  which  is  a  derivative  of 
the  tertiary  series  of  amino-alcohols. 

It  was  discovered  recently  by  M.  Fourneau, 
the  superintendent  of  the  laboratories  of  a  firm 
of  chemists  in  Paris. 

Stovaine  crystallizes  in  small,  brilHant  scales 
which  are  readily  soluble  in  water,  methyl  alcohol, 
and  acetic  ether.     It  is  less  soluble  in  alcohol 
It  is  slightly  acid  in  reaction. 

Aqueous  solutions  of  it  can  be  sterilized  b}- 
prolonged  boiling,  showing  that  stovaine  is  equaL 
at  least  in  stability,  to  cocaine. 

As  regards  toxicity,  stovaine  has  only  about 
one-third  the  toxicity  of  cocaine.  It  possesses 
a  fleeting  vaso-dilator  action  compared  with  the 
markedly  vaso-constrictor  action  of  cocaine,  and, 
in  addition,  possesses  (according  to  Pouchet)  a 
tonic  action  on  the  heart.  It  appears  also  to 
possess  some  antiseptic  and  germicidal  properties. 
In  contra-distinction  to  cocaine,  it  may  be  given 
to  patients  in  the  sitting  position,  and  after  the 
operation  is  completed  there  is  no  danger  in  letting 
the  patient  leave  the  house  and  go  home — no 
risk  of  syncope,  in  short. 

The  strength  of  the  solution  should  be  3  to  4 
per  cent.,  in  distilled  water. 


i86   x\NiESTHESIA  IN  DENTAL  SURGERY 

Novocain. 

Novocain  has  been  used  as  a  substitute  for 
cocaine,  and  improvement  on  eucaine  and  sto- 
vaine,  of  late,  with  such  favourable  results,  that 
it  is  worthy  of  some  notice.  Novocain  is  the 
hydro-chloride  of  para-amido-benzoyl-diethyl- 
amino-ethanol,  represented  by  the  formula — 

NH2C6H4COOC2H4N(C2H5)HCl. 

It  possesses  a  double  claim  to  consideration  as 
a  local  anaesthetic,  being  constituted  both  as  an 
amino-alcohol  and  as  an  ester  of  para-amido- 
benzoic  acid,  each  of  which  classes  of  chemical 
substances  possess  valuable  anaesthetic  properties. 
Novocain  completely  fulfils  the  highest  standard 
of  the  requirements  for  an  ideal  local  anaesthetic : 

1.  Ready  solubility  in  water.  The  solutions 
are  stabile,  sterilizable  by  heat,  and  capable  of 
rapidly  penetrating  the  tissues. 

2.  They  possess  a  low  degree  of  toxicity  in 
proportion  to  their  anaesthetic  power. 

3.  Absolute  freedom  from  irritant  action. 

4.  Physiological  compatibility  with  adrenalin 
preparations. 

In  regard  to  the  last  two  points,  novocain  is 
the  only  local  anaesthetic  which  possesses  these 
qualities. 

Novocain  may  be  heated  to  120"  C.  without 


THE  USE  OF  LOCAL  ANAESTHESIA     187 

decomposition,  and  melts  at  155°  C.  It  is 
soluble  in  its  own  weight  of  water — cold — and 
the  solution  is  neutral  in  character,  and  may  be 
repeatedty  boiled  without  decomposition.  A  5  per 
cent,  aqueous  solution  is  isotonic  \\dth  human 
tissue  fluids,  and  the  osmotic  tension  is  equal  to 
that  of  cocaine  solutions  of  the  same  strength. 

Physiological  Characters. — Braun  considers  this 
drug  as  an  anaesthetic  with  an  ideal  absence  of 
irritating  properties,  and,  by  the  experimental 
investigations  on  animals  and  abundant  clinical 
experience,  has  confirmed  his  Wews.  The  anaes- 
thetic potency  of  novocain  is  much  enhanced 
when  it  is  combined  with  adrenalin.  It  is  ten 
times  less  toxic  to  mankind  than  cocaine,  and  it 
is,  further,  free  from  any  local  irritating  properties. 

There  is  therefore  no  sloughing  or  ulceration, 
nor  any  signs  of  inflammation,  produced  at  the 
site  of  the  injection:  a  most  important — ^indeed, 
essential — matter  in  dental  work. 

For  dental  anaesthesia  a  i  or  2  per  cent,  solu- 
tion of  novocain  with  suprarenin  borate  is 
employed.  Up  to  4  per  cent,  solution  without 
suprarenin  borate  are  used  at  times  with  excellent 
results. 

With  this  drug,  as  with  others,  the  use  of  a 
suitable  syringe  is  most  important,  in  order  that 
suflicient  pressure  may  be  got  up  to  force  the 


i88   ANiESTHESIA  IN  DENTAL  SURGERY 

fluid  far  into  the  tissues.  Several  instrument 
manufacturers  make  excellent  all-metal  syringes 
for  this  purpose. 

It  is  no  more  effectual  than  other  drugs  where 
the  periodontal  membrane  is  acutely  inflamed, 
and  the  best  results  are  always  obtained,  of  course, 
with  subjects  w^ho  are  self-possessed  and  pos* 
sessed  of  common  sense.  Ten  to  fifteen  minims 
of  an  8  per  cent,  solution  is  sufficient  to  anaes- 
thetize a  single  tooth. 

Tfxhnique  of  Local  Anesthesia  by 
Infiltration. 

The  syringe  for  making  injections  into  the  gums 
requires  to  be  somewhat  differently  and  more 
strongly  constructed  than  the  ordinary  hypo- 
dermic syringe,  for  the  tissue  into  which  the  injec- 
tion is  made  is  very  dense,  and  offers  a  consider- 
able degree  of  resistance.  The  syringe  which 
Sauvez  recommends  is  that  of  Pravatz. 

The  armature  of  this  syringe  is  fitted  with  two 
wings,  which  act  as  a  point  d'appui  or  fulcrum 
for  the  middle  and  index  finger,  so  that  greater 
purchase  is  afforded  to  the  thumb,  which  presses 
on  the  end  of  the  piston.  The  surface  of  the  head 
of  the  piston  is  concave  and  solid,  allowing  con- 
siderable pressure  to  be  applied  by  means  of  the 
thumb  or  palm  of  the  hand.     The  needles  are 


THE  USE  OF  LOCAL  ANAESTHESIA     189 

screwed  on,  and  not  simply  slipped  on  (as  in  some 
syringes);  for  in  such  a  union,  if  much  pressure 
be  exercised,  the  fluid  is  allowed  to  escape.  Each 
needle  should'also  be  fitted  with  a  leather  washer, 
so  that,  if  the  butt  is  firmly  screwed  against  this 
washer,  it  is  practically  impossible  for  any  fluid 
to  escape. 

The  glass  barrel  of  the  syringe  is,  moreover, 
partially  surrounded  by  metal,  which  adds  to  the 


FIG.     20. SYRINGE    WITH    EXTENDING    PISTON-ROD. 

(Model  similar  to  Pravatz.)     Reduced  to  \  size. 

strength  of  the  syringe,  while  the  rod  of  the  piston 
is  graduated  in  fractions  of  cubic  centimetres, 
so  that  by  means  of  a  sliding  screw-nut  the 
contents  of  the  syringe  may  be  divided  into  as 
many  parts  as  one  wishes.  As  regards  needles, 
those  made  of  platinum-iridium  have  some 
advantages,  and  can  be  made  red-hot  to  sterilize 
them  if  necessary.  But  they  have  the  disadvan- 
tage of  being  rather  too  thick  and  not  penetrating 


igo   ANAESTHESIA  IN  DENTAL  SURGERY 

the  dense  tissues  easily,  while  the  thin  ones  are 
too  fragile  to  offer  sufficient  resistance  without 
breaking.  Sauvez  only  uses  steel  needles  (as 
regards  his  own  practice),  and  finds  that,  although 
they  also  break  easily,  they  are  preferable  in  the 
end,  on  account  of  the  small  size  of  the  puncture, 
and  of  the  ease  with  which  they  penetrate  the 
tissues.  They  have  the  drawback,  however,  of 
requiring  to  be  changed  too  often.  In  addition 
to  the  straight  needles  which  one  uses  most  often, 
we  have  also  found  very  useful  both  the  curved 
ones  and  those  in  the  form  of  a  bayonet;  but 
these  last  are  very  readily  blocked  up.  Before 
fitting  a  needle  on  to  the  syringe  it  is  necessary 
to  see  if  it  is  quite  clear  or  not,  and  in  order  to  be 
sure  of  this  it  is  usual  to  keep  a  thin  metal  wire 
in  the  lumen  of  it  when  the  needle  is  not  in  use.* 
One  should  b6  quite  sure  that  the  needle  is  sharp, 
and  that  the  sides  are  not  roughened  with  rust, 
which  would  render  the  penetration  of  the  tissues 
more  slow  and  painful.  Platinum-iridium  needles 
have  the  disadvantage  of  blunting  easily  and 
the  point  becoming  turned  back,  and  this  is 
all  the  more  likely  to  happen  when  the  tissues  are 
dense  and  tough. 

The  syringe  should  only  be  used  for  cocaine, 

*  It  is  best  to  use  Schiminel's  needles  with  the  shaft  and 
hilt  in  two  pieces,  and  use  a  fresh  shaft  for  each  patient. 


THE  USE  OF  LOCAL  ANAESTHESIA     191 

and  another  should  be  kept  for  exploratory 
purposes  and  for  the  injection  of  other  drugs,  such 
as  ether  or  caffeine. 

The  Sterilization  of  the  Instrument. 

Antiseptic  precautions  are  not  the  less  necessary 
as  regards  the  S3n:inge  than  the  fluid  to  be  injected. 
Neglect  of  proper  precautions  to  secure  complete 
asepsis  may  have  occasionally  the  most  serious 
consequences.  It  is  more  than  probable  that 
many  iU-effects  of  the  injections,  such  as  delay 
in  healing,  unhealthy  condition  of  the  wound, 
shedding  of  splinters,  wound  infection,  and 
sloughing,  which  are  laid  to  the  score  of  cocaine, 
are  only  due  in  reality  to  neglect  of  these  pre- 
liminary precautions.  In  short,  it  is  only  too 
easy  to  inoculate  a  wound  with  septic  material 
which  remains  on  the  needle  from  a  previous 
operation.  The  asepticity  of  the  instrument 
should  be  secured  in  the  following  manner: 

When  the  operation  is  completed,  the  syringe 
is  placed  in  a  glass  beaker  containing  a  5  per  cent  ^ 
solution  of  carbolic  acid;  the  b  rrel  is  filled  with- 
this  solution,  and  allowed  to  remain  so  for  the 
time  it  is  not  in  use.  A  rigorous  asepsis  is  thus 
secured,  and,  in  addition,  the  packing  of  the  piston 
being  always  immersed  in  fluid  remains  moist  and 
swollen,  and  so  does  not  allow  leakage  alongside 


192    ANESTHESIA  IN  DENTAL  SURGERY 

it  when  in  actual  use.  As  regards  the  needles, 
in  addition  to  putting  them  through  a  flame,  it 
is  well  to  boil  them  for  a  little  in  a  capsule  over  a 
spirit-lamp,  having  put  a  little  boracic  acid  into 
the  capsule. 

Precautions  to  be  observed  before  making 
THE  Injection. 

Before  making  the  injection  we  should  get 
the  patient  to  rinse  his  mouth  out  with  boracic 
lotion,  a  saturated  solution,  or  even  a  solution  of 
1 :  1,000  formalin.  A  piece  of  cotton-wool  dipped 
in  alcohol  and  i:  i,ooo  sublimate  is  then  passed 
over  the  gum  in  order  to  disinfect  the  region, 
which  is  then  dried  with  a  piece  of  anhydrous 
aseptic  wool.  These  preliminary  precautions 
must  not  be  neglected;  they  are  simple,  and  do 
not  really  occasion  loss  of  time,  and,  if  one  carries 
them  out  always,  the  risk  of  any  infection  in  the 
site  of  the  injection  may  be  practically  done  away 
with . 

The  Injection. 

In  the  vast  majority  of  cases  one  can  say  that 
the  actual  prick  of  the  needle  is  quite  painless, 
particularly  when  one  uses  very  fine  and  sharp 
needles.  Nevertheless,  the  puncture  may  be 
painful  enough  at  times,  even  though  the  gum  be 


THE  USE  OF  LOCAL  ANAESTHESIA     193 

not  actually  inflamed — that  is  to  say,  although 
there  be  no  periostitis  or  gingivitis. 

The  patient  sometimes  dreads  this  prick,  and 
starts  violently  when  it  is  made.  It  can  be  ren- 
dered absolutely  without  pain  by  the  following 
means:  (i)  If  the  tooth  is  sensitive  to  cold  from 
caries  or  from  the  pulp  being  laid  bare,  or  if  there 
be  a  neighbouring  tooth  similarly  sensitive  to 
cold,  a  small  lump  of  cotton-wool  soaked  in 
5  to  10  per  cent,  solution  of  cocaine  should  be 
applied  to  the  gum  for  a  minute  or  two.  (2)  If, 
however,  the  tooth  to  be  extracted  is  not  actually 
sensitive  to  cold,  we  can  effect  the  same  by  means 
of  a  spray  of  chloride  of  ethyl.  The  needle  may 
be  safely  put  in  at  the  moment  the  gum  gets 
blanched  and  frozen. 

This  method  is  more  rapid  than  the  first-named ; 
in  addition,  it  restricts  the  circulation  of  the 
cocaine  to  the  immediate  locality,  and  so  renders 
its  action  the  more  efficacious. 

In  order  to  know  where  exactly  to  put  in  the 
needle  and  make  the  injection  efficaciously,  one 
should  know  something  of  the  tissues  which  are 
being  traversed. 

We  will  therefore  briefly  describe  the  mucous 
membrane  covering  the  gums.  It  varies  consider- 
ably according  to  the  region  we  are  examining. 
Speaking  generally,  it  is  intimately  united  to  the 


194   ANAESTHESIA  IN  DENTAL  SURGERY 

periosteum  of  the  jaw  in  the  region  of  the  alveolar 
portion  of  the  teeth,  and  it  is  there  difficult  to 
separate  it  from  the  jaw;  it  thus  belongs  to  the 
fibro-mucosse,  and,   as  regards  its   character,   is 
thick,  hard,  resistant,  and  non-vascular.     In  the 
region  of  the  base  of  the  alveoli  the  periosteum  of 
the  jaw  supplies  a  prolongation  to  each  alveolus, 
which  adlieres  by  one  of  its  surfaces  to  the  sides 
of  the  cavity,  and  by  the  other  to  the  tooth  itself. 
On  the  other  hand,  equally  at  the  base  of  the 
alveolus,    the    mucous    membrane    is    thickened, 
embraces  the  neck  of  the  tooth,  and  thus  meets 
with  a  part  of  the  crown,  forming  around  it  a  ring 
or  even  a  cylinder  3  millimetres  deep,  remarkable 
for  its  thickness,  in  consistence  very  like  fibro- 
cartilage,  and  very  often  inflamed. 

The  reader  will  do  well  to  refer  to  some  treatise 
on  anatomy  in  order  to  render  himself  quite 
familiar  with  the  arrangement  of  the  tissues  in  this 
region.  At  the  palatine  arch  the  mucous  mem- 
brane is  still  more  united  in  its  thickness  to  the 
periosteum,  and  this  union  is  so  deep  and  com- 
plete that  to  separate  one  from  the  other  by  a 
dissection  is  practically  impossible.  We  know 
that  the  gum  is  reflected  on  to  the  inside  of  the 
cheeks  and  lips,  forming  with  them  a  cul-de-sac 
which  limits  above  and  below  the  vestibule  of  the 
mouth.     In  this   region  the   mucous   membrane 


THE  USE  OF  LOCAL  ANAESTHESIA    195 

consequently  leaves  the  periosteum,  and  one  finds 
a  layer  of  tissue  which  infiltrates  very  easily  and 
increases  in  thickness  the  farther  we  get  away 
from  the  actual  alveolar  portion.  Consequently, 
if  an  injection  is  to  be  efficacious  it  must  be  made 
at  a  point  where  the  mucous  membrane  and  the 
periosteum  are  intimately  united,  and  therefore 
not  too  near  the  neck  on  the  one  hand,  nor  above 
or  too  near  the  cul-de-sac  between  the  gums  and 
lips  or  cheeks. 

At  the  moment  of  making  the  injection  the 
syringe  is  held  in  the  hand  like  a  pen,  so  that  a 
point  of  support  may  be  obtained  on  the  jaw  with 
the  middle,  annular,  and  little  fingers. 

Sauvez  directs  that  the  needle  be  inserted 
into  the  mucous  membrane  at  a  point  situated 
as  nearly  as  possible  midway  between  the  free 
border  of  the  gum  and  the  spot  where  the  root  of 
the  tooth  should  be  found,  rather  nearer  the  neck 
of  the  tooth,  and  be  pushed  in  obliquely.  The 
puncture  should  not  be  deep,  and  should  be  made, 
not  Ay/)o  dermic  ally  but  ^;z  dermic  ally ;  indeed, 
the  expression  '  hypodermic  '  should  not  be  used 
in  connection  with  it.  The  piston  of  the  syringe 
is  then  pushed  home  very  gently  and  without 
any  jerks,  and  always  very  slowly,  in  order  that 
time  may  be  allowed  for  the  fluid  which  is  injected 
to  dissipate  itself  in  the  meshes  of  the  tissue.     A 


196   ANAESTHESIA  IN  DENTAL  SURGERY 

good  deal  of  resistance  should  be  experienced  in 
the  tissues  also,  this  being  sometimes  very  great. 
The  needle  is  thrust  in  little  by  little,  keeping  it 
always  in  the  thickness  of  the  skin.  If  the  injec- 
tion is  made  in  this  way,  one  sees,  as  the  piston 
is  gradually  pushed  home,  the  mucous  membrane 
become  white  and  blanched  over  a  certain  area, 
and  the  centre  of  this  zone  may  be  represented 
by  the  point  where  the  needle  was  thrust  in.  Two 
errors  must  be  avoided,  however :  one  is  not  to 
put  the  needle  in  far  enough,  and  the  other  to  put 
it  in  too  much.  If  one  does  not  put  it  in  far 
enough,  the  mucous  membrane  is  seen  to  be  raised 
at  this  point,  but  not  in  its  whole  thickness;  it 
forms  a  cyst  or  '  bleb  '  just  like  that  which  is 
caused  by  a  slight  burn  on  the  skin.  It  is  nearly 
transparent  and  clearly  defined.  If  the  piston  is 
still  thrust  home,  the  blister  bursts  and  the  liquid 
escapes.  If  the  needle  be  withdrawn  and  a 
finger-tip  be  placed  over  the  puncture  to  stop  the 
fluid  from  escaping,  the  anaesthesia  is  sufficient. 
In  certain  regions,  especially  in  the  neighbour- 
hood of  the  first  molar  tooth,  injections  are  difii- 
cult  to  make  in  a  satisfactory  manner.  At  this 
point  the  fibro-mucosa  is  very  thin,  whilst  the 
mucous  membrane,  abandoning  the  periosteum, 
leaves  between  them  a  layer  of  uniting  tissue 
v/hich  is  ver\^  readily  infiltrated,  the  more  so  as 


THE  USE  OF  LOCAL  ANiESTHESL\     197 

the  last  fibres  of  the  buccinator  muscles  lose  them- 
selves there. 

If  one  buries  the  needle  too  deeply  or  too  per- 
pendicularly, it  strikes  against  the  bone,  and  one 
has  to  withdraw  it  with  the  point  gone,  no  fluid 
frequently  having  permeated.  One  may  be 
tolerably  certain  that  the  anaesthesia  will  be 
efficient  if  the  piston  is  hard  to  press  home.  At 
times  one  is  inclined  to  think  that  the  needle  of 
the  syringe  is  blocked,  so  much  pressure  on  the 
piston  is  needed  to  force  in  a  very  small  amount  of 
the  fluid.  If  one  feels  the  liquid  going  in  without 
any  effort,  the  best  way  is  to  withdraw  the  needle 
and  make  a  fresh  puncture,  for  this  indicates  that 
the  needle  is  not  properly  thrust  into  the  gum, 
or  that  there  has  been  a  leakage  of  the  liquid  at 
the  point  where  the  needle  is  screwed  on  to  the 
S3Tinge. 

The  Number  of  Punxtures. 

As  to  the  number  of  punctures  one  should  make, 
it  is  verv  difficult  to  give  any  precise  directions, 
but  one  must  act  differently  according  to  each 
case.  The  only  principle  which  one  can  formulate 
is  that  it  is  necessary,  as  far  as  possible,  to  sur- 
round each  tooth  with  a  zone  of  anaesthesia, 
which  will  necessitate  multiple  punctures.  When 
the  teeth  are  close  together,  one  need  only  make 


igS   ANAESTHESIA  IN  DENTAL  SURGERY 

injections  on  the  inner  and  outer  sides  of  the 
alveolus.  Generally  speaking,  in  this  case  it  is 
most  often  necessary  to  make  several  punctures 
on  each  side.  They  are,  indeed,  quite  sufficient 
when  made  into  a  healthy  mucous  membrane, 
thick  and  resistant.  But  the  majority  of  the 
teeth  which  are  extracted  are  associated  with 
inflammatory  conditions,  which,  if  they  are  not 
acute  at  the  moment  of  extraction,  have,  at  any 
rate,  left  the  mucous  membrane  more  or  less 
affected.  Further,  if  the  injection  is  to  be  made 
in  a  soft  tissue,  flabby,  fungous,  and  infiltrated, 
it  will  be  necessary  to  make  several  punctures. 
One  is  struck  by  the  fact  that  a  single  injection  of 
J  centigramme  in  the  palatine  region  is  quite 
enough  to  secure  a  good  analgesia,  because  the 
tissues  covering  the  bony  arch  are  very  dense, 
while  on  the  external  alveolar  side  several  punc- 
tures are  sometimes  necessary.  If  the  neighbour- 
ing teeth  are  gone,  or  if  only  one  is  gone,  the  needle 
is  inserted  where  the  tooth  was,  care  being  taken 
to  make  the  puncture  perpendicular  to  the  jaw, 
but  in  a  plane  parallel  with  the  mucous  membrane. 
Further,  in  the  case  of  a  tooth  which  is  isolated 
on  all  sides,  one  should  put  the  needle  in  on 
each  aspect  of  the  tooth  if  it  is  to  be  extracted. 
Although  such  a  custom  is  common,  it  is  not 
necessary  to  place  the  tip  of  the  finger  on  the 


THE  USE  OF  LOCAL  ANiESTHESL\     199 

puncture  to  prevent  the  fluid  escaping,  except  in 
the  case  we  have  just  mentioned.  Indeed,  this 
precaution  is  useless  in  the  large  majority  of 
cases,  for  the  fluid  only  tends  to  come  back  when 
difficulty  has  been  experienced  in  introducing  it. 
It  only  escapes  when  it  has  not  penetrated  to  the 
true  mucous  lining,  and  especially  when  a  blister 
has  formed.  In  such  cases,  when  one  withdraws 
the  needle,  the  liquid  escapes  by  the  little  orifice 
just  as  it  does  when  one  punctures  the  cyst  with 
a  needle. 

Some  people  recommend  that  the  finger  should 
be  placed  on  the  point  about  which  the  puncture 
has  been  made,  not  only  after  injecting,  but  even 
at  the  moment  when  one  makes  the  injection,  in 
order  that  one  may  feel  the  mucous  membrane 
being  raised,  and  be  sure  that  the  injection  has 
penetrated  into  the  tissues.  This  is  not  necessary, 
however,  for  the  bleaching  of  the  gum  is  a  sure 
sign  that  the  injection  has  been  properly  made. 
On  the  other  hand,  it  is  very  often  diflicult  to 
stretch  out  the  cheeks  and  push  back  the  tongue 
with  the  mirror.  This  has  to  be  done  when  the 
injection  is  made  on  the  external  alveolar  border 
which  corresponds  to  the  second  and  third  upper 
molar,  and  the  part  of  the  alveolar  margin  which 
corresponds  to  the  large  lower  molars.  On  the 
upper  jaw  one  is  embarrassed  by  the  cheek,  and 


200   ANAESTHESIA  IN  DENTAL  SURGERY 

on  the  lower  by  the  tongue,  so  that  this  use  of  the 
finger  is  not  advantageous. 

If  two  injections  only  are  made — one  on  the 
inner,  and  the  other  on  the  outer  side — ^there  is 
a  practical  point  of  some  moment  which  may  be 
mentioned.  The  needle  is  thrust  into  the  tissue, 
its  point  turned  towards  the  periosteum;  the 
injection  is  then  made  so  as  to  get  a  blanched  area, 
and  then,  giving  the  syringe  half  a  turn  forwards, 
the  injection  is  continued.  In  this  wa}^  a  semi- 
circle of  anaemic  tissue  is  obtained,  which  is  super- 
imposed on  the  first.  The  syringe  is  then  given  a 
complete  turn,  so  that  the  side  which  looks  for- 
ward is  turned  backwards,  and  the  injection  is 
m^ade  anew.  A  third  zone  of  blanched  tissue  is 
formed,  which  is  partly  perimposed  on  the  first. 
We  have  thus  several  ischaemic  zones  superim- 
posed exactly  in  the  region  where  the  analgesia 
should  be  most  complete. 

Although  one  is  obliged  to  employ  several 
punctures  to  get  the  proper  amount  of  analgesia, 
the}^  should  nevertheless  be  reduced  to  a  mini- 
mum. The  place  at  which  they  are  made 
becomes  rapidly  covered  with  blood  from  slight 
haemorrhage,  which  it  may,  however,  be  difficult 
or  tedious  to  arrest.  It  will  be  found,  as  a  general 
rule,  that  four  or  five  punctures  will  suffice,  with 
the  use  of  i  centigramme  of  cocaine,  to  induce  a 


THE  USE  OF  LOCAL  ANAESTHESIA     201 

proper  degree  of  analgesia.  The  injection  having 
been  made,  the  question  then  arises,  'How  long 
should  one  wait  before  proceeding  with  the  extrac- 
tion ?'  It  is  a  common  custom  to  wait  five 
minutes  for  the  cocaine  to  act,  but  this  is  scarcely 
necessary,  in  view  of  the  fact  that,  when  the  injec- 
tions are  properly  made,  some  little  time  is  taken 
up  in  that  way.  If  one  makes  several  injections 
on  the  inner  and  outer  side  of  the  tooth  in  frac- 
tional doses,  even  if  the  extraction  is  commenced 
two  minutes  after  the  last  injection,  an  interval 
of  probably  not  less  than  five  minutes  exists 
between  the  first  injection  and  the  commencement 
of  the  operation. 

As  a  matter  of  fact,  it  is  better  not  to  wait  so 
long  as  five  minutes,  for  during  the  period  of 
waiting  the  patient  is  a  prey  to  certain  apprehen- 
sions and  misgivings,  in  spite  of  all  that  can  be 
said  to  reassure  him. 

During  the  period  of  suspense  it  is  a  good  plan 
to  chat  to  the  patients,  in  order  to  keep  their  mind 
occupied  and  so  avoid  this  pre-operative  anxiety. 
They  may  be  shown  that  they  no  longer  feel  the 
prick  of  the  needle,  and  this  often  produces  on 
them  an  excellent  moral  effect.  They  may  be 
told  also  to  keep  rinsing  out  the  mouth  with  boric 
lotion  or  some  other  antiseptic.  Cases  in  which 
analgesia  is  slow  in  appearance  are  very  rare, 


202    AN.ESTHESIA  IN  DENTAL  SURGERY 

but  one  comes  across  patients  in  whom  cocaine 
analgesia  is  produced  more  slowly  than  with 
others. 

Such  are  the  indications  which  appear  most 
rational  in  all  the  cases  where  there  is  a  healthy 
mucous  membrane,  and  where  the  puncture  is  to 
be  made  in  an  easily  accessible  region.  These 
cases  form,  fortunately,  the  majority  of  those 
with  which  we  have  to  deal ;  but  at  the  same  time 
there  are  some  cases  which  we  come  across  where 
circumstances  render  the  production  of  analgesia 
less  easy,  and  certain  modifications  in  our  methods 
are  required. 

Difficult  Cases. 

We  will  now  deal  with  these,  and  in  such  a 
manner  as  to  complete  our  description  of  the 
technique. 

If  the  gum  is  soft  or  stripped  from  the  alveolus, 
it  is  difficult  to  get  good  results.  One  of  the  finest 
of  needles  must  be  used,  in  order  that  traumatism 
may  be  reduced  to  a  minimum  and  bleeding  be 
avoided,  and  the  fluid  should  be  injected  as  slowly 
as  is  possible.  One  can  attain  this  by  means  of 
a  small,  movable  screw-nut  on  the  piston-rod  of 
the  syringe. 

Inflammation  of  the  gum  is  frequently  caused 
by  the  presence  of  tartar,  and  it  is  in  the  regions 


THE  USE  OF  LOCAL  AN.ESTHESL\     203 

where  this  is  found  that  we  find  the  puncture 
difficult  to  make.  We  know  that  tartar  is  found 
for  the  most  part  in  the  places  where  mastication 
is  carried  on  only  very  little  or  not  at  all,  at 
the  back  of  the  teeth,  which  are  badly  cleaned 
by  the  tongue — that  is  to  say,  on  the  external 
facets  of  the  teeth  in  general,  and  more  particu- 
larly those  which  are  near  the  secretory  orifices  of 
the  salivary  glands  (the  external  facet  of  the 
large  upper  molars,  of  the  incisors  and  lower 
canines). 

The  result  is  that  an  injection  is  difficult  to  make 
on  the  external  alveolar  border  of  teeth  in  general, 
and  in  the  region  of  the  inner  alveolar  border  of 
incisors  and  inferior  canines.  Very  rarely  is  it 
necessary  for  us  to  extract  the  latter;  they  are,  as 
we  know,  the  teeth  which  have  the  least  tendency 
to  caries.  They  disappear  almost  always  only 
at  an  advanced  age,  when  the  rarefaction  of  the 
alveolar  process  makes  them  loose.  Their  re- 
moval is  then  a  painless  matter,  and  therefore  we 
need  not  consider  them  further. 

For  injections  on  the  internal  alveolar  border, 
as  the  gum  is  often  thick  and  soft  here,  one 
should  not  make  the  puncture  far  from  the  actual 
border  in  the  region  of  the  neck  of  the  tooth,  as  it 
will  often  happen  that  here  will  be  found  the  true 
mucous  membrane. 


204    AN.ESTHESIA  IN  DENTAL  SURGERY 

One  should  always  avoid  making  the  puncture 
in  the  cul-de-sac  which  is  formed  by  the  cheek  and 
the  gum;  in  this  region  the  mucous  membrane  is 
separated  from  the  periosteum  by  a  loose  layer 
of  cellular  tissue,  which  is  very  readily  infiltrated, 
as  we  have  previously  remarked ;  and  one  can  only 
find  the  true  dermal  layer  with  a  great  amount 
of  trouble.  Besides,  we  have  seen  that  for  the 
puncture  of  the  inner  side  of  the  gum,  where  the 
mucous  membrane  is  healthy  most  often,  one  need 
only  use  one-third  of  the  syringeful,  and  keep  the 
remaining  two-thirds  for  the  outer  side.  These 
punctures,  made  a  little  distance  from  the  neck, 
ought  to  be  carried  out  in  the  direction  of  the 
nerves  w^hich  supply  the  tooth  which  we  are  to 
extract. 

In  all  cases  where  we  are  confronted  with  a  soft 
and  spongy  gum,  we  ought  not  to  pretend  that 
we  can  produce  a  complete  anaesthesia  by  the  use 
of  cocaine '  alone,  but  we  ought  to  try  to  get 
the  maximum  effect  possible;  and  this  can  only 
be  got  by  the  use  of  the  combined  cocaine  and 
adrenalin  method.  Even  with  cocaine  alone, 
however,  we  can  produce  a  great  diminution  of  the 
pain,  and  we  can  obtain  an  absolute  insensitive- 
ness  if  we  combine  the  injection  of  cocaine  with 
the  use  of  '  coryl '  as  a  freezing  agent. 

When,  however,  there  is  periostitis  and,  above 


THE  USE  OF  LOCAL  ANAESTHESIA     205 

all,  acute  periostitis,  as  the  gum  is  often  hyperaemic 
and  inflamed,  especially  on  the  outer  side,  we 
should  carry  out  the  injection  in  the  manner  we 
have  described,  slowly  and  carefully,  so  as  not 
to  lose  any  of  the  liquid,  and  always  keeping  the 
needle  in  the  dermal  layer.  In  this  case  cocaine 
is  alone  employed,  and  is  preferable,  for  the  pain 
persists  after  the  extraction ;  and  as  the  analgesia 
produced  by  cocaine  lasts  ten  to  fifteen  minutes, 
the  painful  sensation  is  lessened,  while  the  effect 
produced  by  freezing  passes  off  in  a  few  seconds. 

If  an  abscess  exists  in  the  region  of  the  tooth, 
and  a  collection  of  pus  has  already  distinctly 
formed,  it  is  necessary  to  take  certain  precautions 
in  making  the  puncture,  and  for  two  reasons: 
not  only  is  the  puncture  itself  very  painful,  but, 
if  badly  made,  it  does  not  produce  analgesia.  The 
chief  precaution  to  take  is  not  to  penetrate  the 
pouch  of  pus ;  a  hypertension  of  the  liquid  matter 
contained  in  the  pouch  is  produced  if  this  be  done, 
causing  intense  pain.  The  puncture  ought  there- 
fore to  be  made  in  the  side  of  the  abscess.  This 
may  seem  at  first  sight  difficult  to  carry  out,  but 
experience  shows  that  it  is  very  easy.  If  one  sees 
that  the  needle  has  penetrated  the  abscess  cavity 
by  mistake,  it  should  be  withdrawn  and  a  fresh 
puncture  made.  Sauvez  suggests  that  in  such 
cases  the  puncture  be  made  at  a  certain  distance 


2o6   AN.^STHESIA  IN  DENTAL  SURGERY 

from  the  point  where  the  mucous  membrane  has 
been  raised  by  the  abscess,  just  as  in  the  case 
where  the  periosteum  brings  about  the  formation 
of  a  red  band  where  the  mucous  membrane  is 
inflamed ;  it  is  proper  to  make  the  puncture  where 
the  tissues  are  just  healthy,  and  later  one  can  deal 
with  the  affected  area. 

When  a  fistula  exists  opening  on  the  gum  in  the 
vicinity  of  a  tooth  which  one  wishes  to  extract, 
one  finds  often  that  the  fluid  runs  out  through  the 
fistular  orifice  as  it  is  injected.  The  emission  of 
this  fluid  indicates  that  the  needle  has  passed 
between  the  bone  and  the  gum,  and,  as  in  the 
neighbourhood  of  a  fistulous  orifice  the  fibro- 
mucosa  is  often  detached  and  stripped  from  the 
bone,  the  liquid  under  pressure  passes  along  the 
side  and  comes  out  of  the  fistulous  opening  at 
once,  without  having  produced  any  analgesic 
effect.  It  is  necessary  to  withdraw  the  needle 
and  insert  it  more  deeply.  One  will  be  certain 
to  be  into  the  true  derma  when  a  resistance  to  the 
injection  is  experienced,  and  the  fluid  no  longer 
tends  to  escape  by  the  fistulous  orifice.  We  have 
just  passed  in  review  the  different  cases  where  an 
inflammatory  process  of  some  sort  has  caused  a 
modification  in  the  paradental  tissues;  in  other 
cases  the  difficulties  are  in  connection  with  the 
situation  of  the  tooth . 


THE  USE  OF  LOCAL  ANAESTHESIA     207 

The  greatest  difBculties  with  which  one  is  con- 
fronted are  those  which  arise  when  it  is  necessary 
to  make  the  puncture  in  the  vicinity  of  the  external 
alveolar  border  of  the  upper  molars,  or  to  render 
analgesic  the  tissues  surrounding  the  second  and 
third  lower  molars. 

When  one  is  desirous  of  making  an  injection 
into  the  vicinity  of  the  second  or  third  upper 
molar  on  the  external  side,  it  is  necessary  to  tell 
the  patient  not  to  open  his  mouth  too  widely, 
because  by  doing  so  he  will  cause  a  contraction  of 
the  buccinator  muscle,  which  would  come  into 
contact  with  the  outer  alveolar  borders,  and  so 
occlude  the  field  to  be  treated.  The  patient 
should  be  asked  only  to  open  the  mouth  mode- 
rately wide,  and  one  is  then  enabled  to  place  a 
mirror  into  the  space  between  the  gum  and  the 
cheek  which  covers  the  alveolar  border;  this 
mirror  will  push  out  the  cheek,  and  at  the  same 
time  lay  bare  the  region  which  one  wishes  to 
puncture.  It  is  preferable  in  this  particular  case 
to  make  use  of  a  curved  needle,  which  allows  of 
one  seeing  the  point  of  the  needle  in  the  mirror 
so  that  it  may  be  directed  at  will. 

We  are  of  the  opinion  that  it  is  better  to  operate 
thus  than  to  place  on  the  gum  a  linger,  which  is 
by  no  means  always  aseptic,  in  order  to  feel  the 
mucous  membrane  rising.     The  diagram  below 


208   ANiESTHESIA  IN  DENTAL  SURGERY 

shows  better  than  a  prolonged  description  the 
difficulties  which  one  meets  with  when  injecting 
one  of  the  two  lower  molars  at  the  back,  or 
wisdom  teeth.  The  vertical  section  which  we 
give  is  made  between  the  second  and  third  lower 
molars.  Besides,  in  operating  on  the  floor  of  the 
mouth  it  is  difficult  to  see  properly,  and  the 
contact  of  the  mirror  with  the  tongue  or  cheek 


FIG.    21, 


-SECOND    OR    THIRD    UPPER   MOLAR. 

(Vertical  section.) 


causes  in  certain  subjects  a  reflex  nausea  or 
retching,  which  is  very  annoying  to  the  operator. 
When  one  has  made  the  puncture,  one  finds 
that  the  needle  almost  at  once  comes  into  contact 
with  the  alveolus,  whence  it  follows  that  one 
ought  to  make  the  injection  in  a  direction  parallel 
with  the  mucous  membrane,  which  one  can  best 
do  with  a  curved  needle.  On  the  inside,  on  the 
contrary,  there  exists  a  considerable  depression 
limited  above  by  the  posterior  part  of  the  stylo- 


THE  USE  OF  LOCAL  AN^STHESL\     209 

liyoid  ligament.  There,  again,  it  is  unnecessary 
to  make  a  deep  injection ;  it  is  only  necessary  to 
put  the  needle  in  for  2  or  3  centimetres  at  most. 
If  one  makes  the  injection  lower,  the  needle  passes 
through  the  mucous  membrane  which  covers  the 
osseous  crest,  and  comes  out  below  this  crest  all 
the  more  easily,  as  the  mucous  membrane  is  thin 


FIG.    22. SECOND    OR    THIRD    LOWER    MOLAR. 

(Vertical  section.) 

on  this  region.  These  precautions  are  the  more 
necessary  to  render  the  extraction  of  the  last  two 
molars  painless,  as  these  are  firmly  held  in  their 
sockets,  and  as  in  cases  where  the  fluid  does  not 
penetrate  into  the  tissues  it  is  spread  over  the 
mouth,  sometimes  even  to  the  vicinity  of  the 
pharynx,  where  the  bitter  taste  which  it  possesses 
is  much  objected  to  by  the  patient. 

14 


210   ANAESTHESIA  IN  DENTAL  SURGERY 

One  c.c.  of  a  i  per  cent,  cocaine  solution,  freshly 
prepared  in  distilled  water,  seems  to  us  sufficient 
and  necessary  for  dealing  with  the  large  majority 
of  cases,  and  to  avoid  accidents.  The  horizontal 
position  is  absolutely  necessary  if  one  injects  more 
than  I  c.c.  of  cocaine. 

Before  or  after  the  operation  the  patient  should 
be  given  a  liquid  stimulant  of  some  sort,  or  some- 
thing to  eat,  and  be  laid  in  the  horizontal  position 
for  a  quarter  of  an  hour  at  least,  if  only  i  centi- 
gramme of  cocaine  has  been  injected,  and  for  even 
two  or  three  hours  if  the  dose  exceeds  a  centi- 
gramme (Sauvez). 

Local  Anesthesia  by  the  Use  of 
Refrigerating  Agents. 

The  freezing  agents  used  for  this  purpose  are 
methyl  and  ethyl  chloride,  and  various  pro- 
prietary preparations  of  the  two  latter  containing 
varying  proportions  of  them,  such  as  coryl* 
and  anestile  (Bengue). 

Ether  is  seldom  if  ever  used  nowadays  for  local 
analgesia  in  the  mouth,  as  it  is  less  pleasant  and 
less  efficacious  than  a  mixture  of  ethyl  and  methyl 
chloride,  though  these  are  now  rarely  used. 

*  Coryl  is  eth}^!  chloride  mixed  in  such  proportions  as 
to  have  a  boiling-point  of  o°  C.  '  Anestile  '  consists  of 
ethyl  chloride  5  parts,  methyl  chloride  i  part. 


THE  USE  OF  LOCAL  ANiESTHESIA     211 

Chloride  of  Methyl  is  a  colourless  gas  at  all 
ordinary  temperatures  with  an  ethereal  odour, 
very  soluble  in  alcohol,  and  somewhat  soluble  in 
water.  It  requires  to  be  kept  in  strong  metal 
cylinders  capable  of  sustaining  a  heavy  pressure. 
Owing  to  the  difficulties  of  storage,  from  extreme 
volatility  and  the  extremely  intense  cold  which  it 
produces,  methyl  chloride  is  not  commonly  used 
alone,  at  any  rate,  in  dental  surgery.  By  direct- 
ing a  stream  of  methyl  chloride  on  to  any  tissue, 
a  lowering  of  tem_perature  as  great  as  50°  to  60°  C 
below  zero  is  produced  very  rapidly,  with  com- 
plete refrigeration.  The  degree  of  refrigeration 
is  very  difficult  to  regulate,  and  may  be  so  severe 
as  to  cause  complete  disorganization  of  the  tissue 
or  even  the  formation  of  a  complete  eschar. 
Fortunately,  methods  have  been  devised  which 
overcome,  to  a  great  extent,  this  drawback  of 
methyl  chloride.  The  drug  is  put  into  a  glass 
vessel  specially  made  for  the  purpose,  known  as 
a  thermo-isolater,  because  it  prevents  the  access  of 
warmth  and  lessens  the  evaporation  of  the  liquid. 
With  the  methyl  chloride  a  small  quantity  of 
ether  is  mixed,  and  the  mixture  thus  formed  is 
applied  to  the  inside  and  outside  of  the  gum  by 
means  of  tampons  of  cotton-wool  covered  with  a 
fine  net  of  silk  and  carried  on  a  wooden  handle. 
The  tampon  is  dipped  into  the  methyl  chloride 


212    ANAESTHESIA  IN  DENTAL  SURGERY 

mixture,  and,  after  being  fairly  saturated,  is 
applied  for  one  or  two  minutes  to  the  surface  of  the 
gum.  On  removing  it,  if  the  proper  degree  of 
freezing  be  produced,  a  white  patch  will  have 
formed  on  the  mucous  membrane,  and  the  surface 
of  the  gum  will  be  quite  insensitive.  Even  with 
these  precautions,  however,  it  is  difficult  to  exactly 
graduate  the  refrigeration  and  to  localize  it. 

Chloride  of  Ethyl. — The  chloride  of  ethyl  used 
for  local  anaesthesia  is  identical  chemically  with 
the  drug  which  is  now  utilized  for  inhalation  pur- 
poses, although  the  latter  is  somewhat  more  care- 
fully prepared.  It  was  employed  for  local  anaes- 
thesia as  far  back  as  1866  by  Rottenstein;  later 
on  Redard  drew  attention  to  its  value,  and  in 
1 89 1  Meng  employed  it  for  local  analgesia  at  the 
Paris  Dental  School.  It  was  all  the  more  readily 
taken  to  at  this  time  owing  to  the  bad  repute  of 
cocaine,  in  connection  with  which  so  many  acci- 
dents had  happened. 

Owing  to  the  extreme  volatility  of  the  drug,  it 
requires  to  be  very  carefully  put  up.  It  is  usually 
dispensed  in  small  glass  cylinders  containing  from 
30  to  60  c.c,  with  a  capillary  tube  opening  at  one 
or  both  ends,  and  a  metal  screw-stopper  with  a 
smaU  washer  of  cork  or  metal.  If  there  are  open- 
ings at  both  ends  the  tube  can  be  refilled.  The 
capillary  tube  for  exit  is  extremely  fine,  and  there 


THE  USE  OF  LOCAL  ANAESTHESIA    213 

is  no  known  filament  which  can  be  passed  through 
it.     It  is  about  ^-Jq-o  ii^^h  in  diameter. 

The  cyHnders  are  very  fragile,  and  very  apt 
to  be  broken  or  to  burst  in  hot  water.  Metal 
cylinders  are  also  used  and  are  in  some  ways 
preferable. 

Method  of  Application:  The  surface  of  the 
gums  is  dried  with  a  piece  of  cotton-wool, 
and  a  piece  of  cotton-wool  is  arranged  in  the 
mouth  so  as  to  prevent  the  ethyl  chloride 
stream  being  projected  against  the  fauces.  The 
cylinder  is  held  in  the  palm  of  the  hand,  and  with 
the  nozzle  directed  downwards;  the  stopper 
Having  been  removed,  the  jet  is  first  directed 
against  the  napkin  or  bib  on  the  patient's  chest, 
and  then  rapidly  turned  upwards  towards  the 
region  of  the  gum  which  one  wishes  to  freeze^ 
holding  it  about  10  to  12  inches  from  the  patient's 
face.  In  this  way  one  avoids  the  risk  of  directing 
it  into  the  eye  of  the  patient,  which,  though  harm- 
less, is  painful  for  the  patient. 

It  is  important  not  to  hold  the  flask  too  near  the 
patient's  face,  as  if  this  is  done  the  ethyl  chloride 
reaches  the  gum,  not  in  the  form  of  a  spray,  but 
in  a  steady  stream,  and  is  wasted,  while  analgesia 
is  slowly  produced,  and  is  evanescent  in  character. 

As  the  hand  of  the  operator  may  be,  or  becomes, 
shaky,  it  is  well  to  have  some  sort  of  support  on 


214   AN.ESTHESIA  IN  DENTAL  SURGERY 

which  to  steady  it.  When  the  gum  on  one  side 
has  become  white  and  frozen,  attention  may  be 
directed  to  the  other  side,  care  being  taken  to 
occasionally  direct  the  spray  against  the  frozen 
side,  in  order  that  it  may  not  become  thawed 
before  the  other  is  ready.  Complete  freezing 
having  been  obtained,  the  flask  is  quickly  laid 
down  or  handed  to  an  assistant,  and  the  opera- 
tion proceeded  with. 

When  one  is  accustomed  to  using  ethyl  chloride 
as  a  refrigerating  agent,  and  if  care  be  taken  to 
wait  sufficiently  long  for  proper  freezing  to  take 
place,  it  is  found  that  by  means  of  it  the  pain 
occasioned  by  the  extraction  of  a  tooth  is  greatly 
diminished.  Its  use  is,  however,  practically 
restricted  to  the  anterior  part  of  the  mouth,  and 
back  teeth  are  not  suitable.  Moreover,  it  is 
practically  impossible  to  prevent  some  of  the  drug 
from  flowing  over  into  the  mouth  and  mixing 
with  the  saliva,  which  some  patients  will  object 
to  considerably.  It  is,  of  course,  useless  and 
strongly  contra-indicated  in  acutely  inflamed 
teeth,  where  the  access  of  cold  causes  much  pain 
to  the  patient.  It  is  most  useful  for  cases  in 
which  a  number  of  loose  and  fragmentary  roots 
have  to  be  removed,  especially  in  timorous 
patients. 


THE  USE  OF  LOCAL  AN.^STHESL\     215 

Indications  and  Contra-indications  for  Re- 
frigeration AND  Cocaine  Anesthesia. 

Freezing  agents  are  better  not  used  in  the  follow- 
ing cases  also : 

1.  When  the  patient  cannot  breathe,  except 
with  difficulty,  through  the  nose. 

2.  When  the  patient  is  a  young  child  or  a  very 
nervous,  timid  person,  for  with  such  people  the 
sight  of  the  apparatus,  the  sensation  of  great  cold, 
and  the  smell  and  taste  of  the  drug  in  the  mouth 
cause  alarm  and  restiveness,  and  sufficient  time  is 
not  allowed  to  produce  proper  freezing. 

3.  If  the  pulp  of  a  tooth  is  sensitive  to  cold,  or 
if  the  tooth  to  be  removed  is  close  to  another  with 
a  sensitive  pulp.  Moreover,  if  the  pulp  is  sensi- 
tive, there  is  neither  advanced  caries,  abscess,  nor 
fistula,  and  cocaine  will  act  particularly  well  in 
such  a  case.  In  hospital  practice,  of  course,  teeth 
with  the  pulp  laid  bare  are  frequently  extracted, 
but  such  cases  are  less  common  among  private 
patients,  and  should  be  increasingly  so. 

4.  When  the  pain  produced  by  the  extraction 
may  last  a  long  time,  as  in  a  case  of  acute  peri- 
odontitis, an  extensive  extraction,  or  the  removal 
of  a  large  molar  with  separate  roots.  Here  the 
action  of  a  freezing  agent  would  be  too  brief,  and 
cocaine  would  be  more  satisfactory. 


2i6    ANAESTHESIA  IN  DENTAL  SURGERY 

5.  When  the  tooth  to  be  removed  is  a  second  or 
third  molar,  with  an  operator  not  thoroughly 
familiar  with  the  use  of  coryl,  etc.,  and  a  nervous 
patient,  who  has  not  sufficient  self-control  to 
abstain  from  movements  of  deglutition,  etc.,  in 
consequence  of  the  irritation  set  up  by  the  drug 
used  for  spraying. 

Freezing  agents  are  specially  contra-indicated 
for  the  extraction  of  the  lower  molars,  especially 
when  the  patient  has  a  tendency  to  the  excessive 
secretion  of  saliva. 

6.  When  the  actual  cautery  is  to  be  used. 
Cocaine  is  contra-indicated — 

1.  In  patients  afflicted  with  cardiac  affections, 
with  aortic  disease  especially,  and  those  with  a 
weak  myocardium. 

2.  In  neurasthenic  patients. 

3.  In  ansemic  and  debilitated  people. 

4.  In  those  affected  with  acute  or  chronic 
disease  of  the  lungs  and  organs  of  respiration. 

5.  In  the  obese  and  women  who  are  suckling. 
Refrigerating  agents  may  take  the  place  of  cocaine 

in  the  following  cases — 

I.  The  injection  of  cocaine  is  difficult  to  make 
when  the  gums  of  the  patient  are  soft  and  fun- 
gating.  Now,  it  is  especially  this  condition  of 
the  gums  which  one  meets  with  on  the  external 
alveolar  border,  and  this  is  the  most  suitable 
region  for  the  application  of  freezing  agents. 


THE  USE  OF  LOCAL  ANAESTHESIA     217 

2.  When  an  abscess  has  formed  in  connection 
with  a  tooth,  it  is  usually  due  to  the  presence  of 
advanced  caries  of  the  fourth  degree,  and  con- 
sequentty  the  pulp  does  not  exist  any  longer, 
and  any  sensibility  to  cold  has  completely  dis- 
appeared; in  such  a  case  a  refrigerating  agent 
such  as  coryl  may  be  used  with  advantage,  more 
especially  as  the  abscess  is  formed  almost  always 
(except  in  the  lateral  incisors  of  the  upper  jaw) 
on  the  outside  of  the  alveolar  border,  and  causes 
the  mucous  membrane  to  bulge  just  at  the  point 
where  it  is  easiest  to  produce  freezing.  The  same 
remarks  apply  to  fistulae,  which  are  almost  in- 
variably due  to  the  pre-existence  of  an  abscess. 

3.  As  regards  the  position  of  the  tooth  to  be 
extracted,  difhculties  will  have  to  be  encountered 
whatever  method  of  local  anaesthesia  be  employed. 


CHAPTER  IX 

THE  ACCIDENTS  OF  ANAESTHESIA 

The  two  chief  troubles  involving  anxiety  to  the 
dentist  and  anaesthetist  and  risk  to  the  life  of  the 
patient  during  anaesthetic  work  are — (i)  Syncope; 
(2)  Asphyxia. 

The  Symptoms  of  syncope  may  be  summarized 
as  follows :  Sudden  dilatation  of  the  pupil,  extreme 
pallor,  muscular  relaxation,  failure  of  the  pulse, 
and  shallow  breathing. 

Treatment. — Prone  position,  tongue  traction, 
artificial  respiration,  lip  rubbing,  hypodermic  of 
pituitrin  or  strychnine,  or  a  hot  saline  enema. 

Signs  and  Symptoms  of  asphyxia  may  be  sum- 
marized as  follows :  Increasing  duskiness  of  com- 
plexion, violent  respiratory  efforts,  and  gradual 
pulse  failure. 

Treatment. — Removal  of  foreign  bodies,  mucus, 
or  blood,  from  air-way,  tongue  traction,  com- 
pression of  the  chest  or  artificial  respiration 
(Sylvester's  or  Schafer's  method),  and  if  need  be 
laryngotomy. 

218 


THE  ACCIDENTS  OF  ANAESTHESIA   219 

Syncope. 

If  the  lines  of  practice  laid  down  in  this  work 
be  followed,  and  the  use  of  chloroform  avoided 
altogether,  if  possible,  and  that  of  ethyl  chloride 
made  with  discretion  and  skill,  cases  of  syncope 
must  be  very  rare  indeed.  Still,  every  dental 
surgeon  should  know  how  to  deal  with  the  con- 
dition if  it  arises — and  it  may  arise  at  any  time. 
Patients  have  died  from  syncope  in  a  barber's 
chair,  and  may  do  so  in  a  dentist's  with  no  an- 
cillary aid  from  anaesthetics. 

Cases  of  fatty  heart  have  to  be  borne  in  mind, 
but  let  not  every  person  who  is  obese  be  regarded 
as  a  subject  of  this  grave  disorder. 

Another  condition  which  may  call  for  care  and 
give  rise  to  grave  anxiety  is  what  is  known  as 
the  status  lymphaticus — too  often  only  *  diag- 
nosed '  at  the  post-mortem.  The  patients  are 
often  the  victims  of  considerable  overdevelop- 
ment of  adenoid  tissue,  involving  enlarged  tonsils 
and  adenoid  growths  in  the  naso-pharynx.  They 
are  usually  mouth-breathers,  highly  nervous,  with 
a  quick,  soft  pulse. 

A  dental  surgeon  cannot  be  expected  to  take 
in  all  these  things,  and  a  few  others,  at  a  glance, 
but  it  is  as  well  as  a  matter  of  practice  for  him 
to  take  stock  of  the  patient's  physical  condition 


220    ANESTHESIA  IN  DENTAL  SURGERY 

before  entering  into  the  question  of  anaesthesia, 
and  if  necessary  call  in  the  assistance  of  a  medical 
colleague  or  anaesthetist. 

As  regards  symptoms  and  signs,  they  are  sum- 
marized above,  and  very  little  more  need  be  said 
about  them.  Most  people  are  familiar  with 
the  appearance  of  a  person  who  has  fainted. 
There  is  the  same  feeble,  fluttering  pulse,  great 
pallor,  relaxed  extremities,  dilated  pupils,  cold, 
clammy  perspiration,  and  feeble,  shallow  respira- 
tions, which  sometimes  die  away  completely. 
The  signs  and  symptoms  of  ordinary  fainting  and 
a  severe  syncopic  attack  vary  but  in  degree, 
and  the  former  may  readily  pass  into  the  latter. 
If  the  attack  come  on  during  the  course  of  a 
n  .rous  oxide  or  gas  and  ether  aucesthesia,  the 
change  in  the  facial  colour  is  not  so  great,  nor 
has  it  so  much  the  ashy  hue  of  death,  owing  to 
pre-existing  lividity.  The  alteration  in  the  nature 
of  the  respirations  is  very  marked,  for  from  being 
quick,  noisy,  or  even  stertorous,  they  suddenly 
disappear  or  become  very  shallow  in  character. 
In  the  anaesthesia  of  chloroform  syncope  may 
occur  with  lightning  rapidity,  and  the  pupils 
dilate  and  respiration  and  pulse  cease  practically 
simultaneously. 

Treatment. — The    cessation    of    breathing    for 
longer  than  a  few  seconds  often  responds  to  the 


THE  ACCIDENTS  OF  ANiESTHESIA      221 

simple  pressure  of  the  hand  on  the  chest  walL 
If  this  is  not  immediately  successful,  however 
and  symptoms  of  cardiac  failure  are  also  noticed, 
prompt  measures  are  essential  in  order  to  prevent 
a  fatal  syncope,  and  the  success  following  them 
will  depend  largely  on  the  vigour  and  rapidity 
with  which  they  are  carried  out. 

The  patient  should  be  instantly  placed  on  his 
back,  with  the  head  lower  than  the  body  and  hang- 
ing over  the  end  of  a  couch  or  table  or  extended 
dental  chair.  The  mouth  should  be  opened, 
tongue  drawn  well  forward  with  a  forceps,  and  the 
chest  rhythmically  compressed. 

Fresh  air  should  be  freely  admitted  by  the 
doors  and  windows. 

A  capsule  of  amyl  nitrite  should  be  cracked  and 
held  to  the  patient's  nostrils,  or  a  little  strong 
ammonia  similarly  applied  on  a  glass  stopper. 

All  clothing  hampering  the  chest  and  abdomen 
should  be  rapidly  removed,  and  the  face  and  chest 
wall  smartly  slapped  with  a  wet  towel  or  napkin. 

In  the  very  large  majority  of  cases,  fortunately, 
the  above  treatment,  properly  carried  out,  will 
suffice  to  restore  pulse  and  breathing.  The 
patient  will  then  simply  require  to  be  kept  warm 
and  be  supplied  with  plenty  of  fresh  air. 

If  these  efforts  are  unavailing,  however,  you 
must  by  no  means  be  discouraged,  but  immedi- 


222     ANAESTHESIA  IN  DENTAL  SURGERY 

ately  resort  to  efficient  and,  if  needed,  prolonged 
artificial  respiration. 

Sylvester's  Method. — The  patient  lying  supine 
on  the  floor  or  on  a  table,  a  pillow  or  folded  coat 
should  be  slipped  beneath  the  shoulders,  so  that 
the  head  hangs  down  and  the  neck  is  extended. 

The  tongue  must  be  kept  well  drawn  forward 
the  whole  time.  This  may  be  effected  with  a  simple 
rubber  band  over  the  tongue  and  under  the  lower 
jaw,  or  by  means  of  an  assistant  with  tongue 
forceps. 

The  operator  should  stand  behind  the  patient, 
grasp  the  arms  about  midway  between  the 
shoulders  and  elbows,  and  press  them  firmly  into 
the  sides  of  the  thorax,  rotating  them  at  the  same 
time  outwards.  Maintain  this  position  for  a 
couple  of  seconds,  while  the  assistant  forces  the 
diaphragm  upwards  by  pressure  on  the  abdomen 
the  while;  then  steadily  draw  the  arms  upwards 
and  outwards  until  they  meet  above  the  head  of 
the  patient,  at  the  same  time  slightly  lifting  him 
from  the  ground,  the  assistant  at  this  point 
releasing  the  pressure  on  the  abdomen.  The 
downward  movement  is  then  repeated,  and  this 
is  kept  up  at  the  rate  of  sixteen  to  the  minute, 
care  being  taken  not  to  overdo  the  pace. 

Hot  and  cold  water  may  be  dashed  over  the 
chest  alternately,  or  hot  cloths  applied  over  the 


THE  ACCIDENTS  OF  ANAESTHESIA    223 

praecordia.  Faradism  of  the  phrenic,  often  advo- 
cated, is  of  doubtful  value,  and  batteries  are  not 
usually  at  hand,  or,  if  at  hand,  in  working  order. 
The  lips  should  be  rubbed  with  a  towel  or  mois- 
tened with  brandy,  a  hot -water  bottle  applied  to 
the  feet,  and  10  ounces  of  plain  hot  water  or  saline 
injected  into  the  rectum  by  means  of  an  ordinary 
Higginson  syringe.  This  last  is  a  most  valuable 
measure.  Injections  of  pituitrin  are  useful, 
suitable  ampoules  being  retailed  by  Messrs. 
Burroughs  and  Wellcome,  and  10  minims  of  the 
I  :  100  liq.  strychninae  may  be  injected  as  an 
alternative.  Dr.  Gordon  Sharpe,  of  Leeds,  advo- 
cates heroic  doses  of  this  drug. 

Asphyxia. 

Mechanical  obstruction  is  almost  invariably 
the  cause  of  asphyxia  occurring  during  the  course 
of  anaesthesia  in  dental  work  induced  by  nitrous 
oxide  or  ether.  In  ethyl  chloride  we  sometimes 
get  a  fairly  early  asphyxia  or  respiratory  failure 
due  to  spasm  of  the  respiratory  muscles,  etc., 
which  is  again  probably  due  to  overdose  for  the 
individual. 

Asphyxial  conditions  are  more  common,  how- 
ever, in  the  recovery  stage  of  anaesthesia,  and 
signaHzed  by  increase  of  cyanosis  and  lividity. 
Careful  sponging,  the  removal  of  all  loose  teeth 


224    AN.ESTHESIA  IN  DENTAL  SURGERY 

and  fragments  of  teeth,  and  the  restriction  of 
bleeding,  are  obviously  important  factors  in 
avoiding  asphyxia. 

One  of  the  authors  recalls  a  case  which  caused 
him  very  great  anxiety  at  the  time,  due  to  the 
patient  vomiting  when  half  under  and  filling  the 
face-piece  and  air-way  with  the  undigested  rem- 
nants of  his  breakfast. 

Whatever  may  be  the  cause,  however,  there  is  a 
clear  indication  on  all  occasions.  The  patient 
wants  air,  and  the  air-way  must  be  cleared  at 
once  and  his  breathing  carried  on  for  him. 

Signs  of  Commencing  Asphyxia. — Increase  or 
return  of  the  lividity,  which  rapidly  extends  all 
over  the  surface  of  the  patient's  body;  gasping 
and  struggling  for  breath,  terminating  in  actual 
convulsions  and  in  cessation  of  respiration.  The 
violent  respiratory  efforts,  as  weU  as  the  non- 
oxygenation  of  the  blood,  themselves  act  as  cardiac 
depressants,  and  the  heart's  action  is  seriously 
impeded  and  finally  stops. 

It  must  be  borne  in  mind  that  the  actual  move- 
ments of  the  chest  may  continue  in  spite  of  the 
complete  occlusion  of  the  larynx,  and  we  must 
therefore  rely  only  on  the  audible  respiratory 
sounds  for  evidence  that  air  is  entering  the  lungs. 

Treatment  of  Asphyxia.  —  Prevention  being 
better  than  cure,  all  possible  precautions  should 


THE  ACCIDENTS  OF  ANiESTHESIA    225 

be  taken  at  all  times  as  regards  dental  props 
and  loose  teeth  in  the  mouth  when  an  extraction 
is  going  on  under  general  anaesthesia. 

The  average  anaesthetist  regards  the  passing  of 
a  tooth  down  the  patient's  air-passages  as  the 
gravest  risk  during  anaesthesia  for  dental  purposes. 
A  tooth  down  the  air-passages  may  cause  spasm 
of  the  glottis,  calling  for  an  immediate  tracheo- 
tomy, and  lead  later  to  a  painfully  protracted 
septic  pneumonia  involving,  as  we  have  known 
it,  years  of  illness  and  subsequent .  litigation. 
We  have  often  trembled  at  the  haphazard  way 
some  extractors,  especially  students,  have  left 
portions  of  teeth  or  whole  teeth  lying  around  the 
patient's  mouth  while  they  completed  an  extrac- 
tion. The  Trewby  Dennis  oral  shield  and  Carter's 
net  spoon  are  useful  in  preventing  teeth  jumping 
back  into  the  throat,  as  the  lower  bicuspids  are 
specially  apt  to  do. 

As  regards  the  immediate  treatment  of  asphyx- 
ial  conditions,  the  first  steps  are,  as  indicated 
above,  to  clear  the  air-way  and  carry  on  the 
breathing.  If  the  blood,  mucus,  or  foreign  body 
be  within  reach  it  should  be  removed  by  appro- 
priate measures — finger,  throat  forceps,  or  sponge. 
Assistance  may  be  given  by  the  old-fashioned 
smack  on  the  back. 

The  offending  body  may  be  rapidly  expelled  by 

15 


226   AN.ESTHESIA  IN  DENTAL  SURGERY 

the  coughing,  and  complete  rehef  be  afforded,  or 
the  dyspnoea  may  pass  off  suddenly  owing  to  the 
position  of  the  foreign  body  becoming  altered. 
On  the  other  hand,  if  the  dyspncea  increases, 
immediate  relief  will  be  called  for  by  tracheotomy 
or  laryngotomy;  in  young  people  inversion  should 
first  be  tried,  but  with  adults  this  is  often  practi- 
cally impossible  and  waste  of  time. 

The  patient  should  be  laid  on  the  floor,  shoulders 
raised  and  head  extended,  and  the  larynx  should 
be  opened  between  the  thyroid  and  cricoid  carti- 
lages; a  tube,  if  available,  should  be  inserted — 
or  failing  this  a  clean  toothpick — or  the  wound 
edges  kept  carefully  retracted  by  means  of  a  bent 
hairpin  or  hook.  Artificial  respiration  should 
then  be  started. 

If  the  respiratory  difficulty  is  due  to  thick 
tenacious  mucus  or  partially  clotted  blood  and 
mucus  sticking  about  the  pharynx,  the  patient's 
head  should  be  bent  forward,  and  he  should  be 
encouraged  to  cough  and  smacked  on  the  back. 
If  this  fails,  a  coarse,  dry  sponge  on  a  handle 
should  be  thrust  well  back  into  the  pharynx  and 
withdrawn  rapidly  with  a  sweeping  movement. 
If  this  be  done,  the  operator  should  be  quite  clear 
that  the  obstruction  is  not  due  to  a  solid  body — 
loose  tooth  or  the  like — or  more  harm  than  good 
may  result.     Apart  from  foreign  bodies^  mucus, 


THE  ACCIDENTS  OF  ANESTHESIA    227 

and  blood,  it.  must  be  borne  in  mind  that  asphyxial 
symptoms  may  be  produced  by  spasm  of  the 
aryteno-epiglottidean  folds  (especially  in  chloro- 
form anaesthesia  in  young  people,  infants,  and  the 
like),  and  here  the  remedy,  as  originally  pointed 
out  by  Lord  Lister  many  years  ago,  is  simple 
rhythmic  traction  of  the  tongue. 


CHAPTER  X 

THE  L.D.S.  DIPLOMA  AND  THE  ADMINIS- 
TRATION OF  ANESTHETICS 

How  far  are  dentists,  holding  the  L.D.S.  diploma 
only,  legally  entitled  to  administer  anaesthetics  ? 

It  is  often  held  that  this  diploma  confers  the 
right  to  administer  nitrous  oxide,  but  no  other 
anaesthetic.  For  this  idea,  however,  there  is  no 
actual  legal  basis,  but  it  has  grown  out  of  the  fact 
that  nitrous  oxide  is  commonly  regarded  as  one 
of  the  dentist's  '  tools,'  and  practically  a  part  and 
parcel  of  his  calling. 

The  law  is  absolutely  ambiguous  on  the  point, 
and  in  the  few  cases  in  which  a  fatality  has 
occurred  and  which  have  actually  come  into  court 
to  be  decided  upon,  the  decision  of  the  presiding 
judge  has  largely  hinged  on  the  amount  of  skill 
presumably  possessed  by  the  person  responsible 
for  the  anaesthetic,  and  little  account  has  been 
taken  of  the  fact  whether  the  person  administering 
the  anaesthetic  actually  had  any  qualification  or 
not  in  the  way  of  a  diploma.     The  fact  is,  of 

228 


THE  L.D.S.  DIPLOMA  229 

course,  that  a  judge  is  scarcely  capable  of  dealing 
with  such  a  technical  matter,  and  he  is  not  in  a 
position  to  say  whether  any  case  was  conducted 
with  a  proper  amount  of  skill  or  not. 

In  the  Metropolis  it  has  for  many  years  past 
been  the  custom  for  a  dentist  in  good  class 
practice  to  ask  the  help  of  a  professional  anaes- 
thetist, whenever  a  patient  comes  to  him  requiring 
gas  or  any  other  anaesthetic,  or  at  any  rate  to 
get  a  medical  practitioner  of  rather  more  than 
ordinary  experience  in  anaesthetic  work  to  help 
him.  In  the  provinces  of  England,  also,  it  has 
been  usual  to  ask  either  the  patient's  own  doctor 
or  a  neighbouring  medical  practitioner  to  be 
present,  and,  if  possible,  to  assist  in  giving  the 
anaesthetic  which  was  required,  even  if  it  were 
only  nitrous  oxide.  We  believe  this  to  be  largely 
due  to  the  inevitable  coroner's  inquest  if  a  fatality 
occurs — an  ordeal  which  has  not  to  be  faced  in 
Scotland.  In  this  country  practice  differs  con- 
siderably. Dental  surgeons  almost  invariably 
give  gas,  and  if  the  extraction  be  not  very  com- 
plicated they  even  administer  gas  and  ether,  and 
ethyl  chloride  and  ether,  themselves.  Indeed, 
since  the  introduction  of  ethyl  chloride  during 
the  past  two  years,  this  anaesthetic  has  been 
administered  broadcast  by  the  dental  surgeons 
holding  the  L.D.S.  diploma,  and  even  by  dentists 


230   ANAESTHESIA  IN  DENTAL  SURGERY 

holding  no  qualification  whatever.  Only  in 
exceptional  and  prolonged  cases  has  it  been  the 
custom  to  ask  for  outside  assistance  on  the  part 
of  medical  men  or  a  special  anaesthetist.  Cases 
have  occurred  in  which  patients  suffering  from 
grave  cardiac  and  respiratory  disability  have  gone 
to  their  dentists,  and  on  the  removal  of  one  or 
more  teeth  being  decided  on,  gas,  gas  and  ether, 
or  ethyl  chloride  and  ether,  has  been  given  on  the 
spot,  in  the  most  offhand  manner.  That  fatalities 
have  occurred  is  not  to  be  wondered  at,  and  this 
is  surely  a  state  of  matters  which  should  not  be 
permitted  to  continue. 

The  dental  profession  is  scarcely  to  be  blamed 
altogether  for  the  position  which  has  arisen. 
Until  ten  or  twelve  years  ago,  at  any  rate,  to  ask  a 
medical  practitioner  in  Scotland  to  give  an  anaes- 
thetic for  a  dental  or  any  other  operation  meant, 
in  ninety-five  cases  out  of  a  hundred,  chloroform. 
So  many  fatalities  have  occurred  in  dental  practice 
under  this  anaesthetic  that  there  is  a  marked 
tendency  to  fight  shy  of  it  on  the  part  of  dental 
surgeons  at  the  present  time,  and  they,  having  so 
far  made  themselves  familiar  with  modern  anaes- 
thetic methods — and  as  regards  their  knowledge 
in  this  respect  being  rather  in  advance  of  the  bulk 
of  the  members  of  the  sister  profession  of  medicine 
• — are  at  the  present  moment  somewhat  inclined 


THE  L.D.S.  DIPLOMA  231 

to  take  the  law  in  their  own  hands,  and  be  respon- 
sible both  for  the  anccsthetic  and  the  operation. 
This  is  very  unfortunate  in  many  ways.  For  one 
thing,  no  one  who  is  going  to  carry  out  an  opera- 
tion, be  it  the  extraction  of  a  number  of  teeth  or 
otherwise,  should  be  responsible  for  the  anaesthetic 
also ;  the  risk  to  the  patient  under  such  conditions 
is  greatly  increased. 

Patients  have  been  known  to  die  during  nitrous 
oxide  anaesthesia,  just  while  a  tooth  was  being 
extracted,  without  the  operator  being  aware  of  it. 
A  case  such  as  this  occurred  some  years  back, 
where,  although  the  patient  must  have  obviously 
been  becoming  rapidly  asphyxiated,  the  person 
extracting  the  teeth  (an  unqualified  dentist)  was 
so  much  taken  up  with  his  work  at  the  moment 
that  he  failed  to  recognize  the  patient's  dangerous 
condition  until  it  was  too  late.  Had  a  responsible 
person  been  superintending  the  anaesthesia,  and 
prompt  measures  been  taken,  there  is  no  doubt 
that  an  accident  would  have  easily  been  avoided. 
The  medical  profession,  and  more  especially  those 
responsible  for  medical  education,  are  undoubt- 
edly to  blame  for  the  state  of  matters  which  exists. 
Until  recently  no  attempt  has  been  made  to  see 
that  candidates  for  the  qualifying  medical  diploma 
have  familiarized  themselves  with  the  better- 
known  anaesthetic  agents,  and,  indeed,  the  ignor- 


232   ANESTHESIA  IN  DENTAL  SURCiERY 

ance  of  the  average  medical  practitioner  of  such 
a  commonly  used  anaesthetic  as  nitrous  oxide  has 
been  notorious. 

A  step  in  the  right  direction  has  now  been  taken, 
however,  in  seeing  that  practical  instruction  in 
anaesthetic  work  is  carried  out  at  the  various 
teaching  hospitals,  and  we  may  hope  that  in  a  year 
or  two  the  lamentable  state  of  ignorance  which 
has  existed  will  be  a  thing  entirely  of  the  past. 
When  the  dental  profession  realizes  that  they, 
individually,  have  a  medical  practitioner  at  hand 
ready  to  intelligently  help  them  with  the  manage- 
ment of  the  anaesthetic  at  any  time,  they  will 
doubtless,  in  their  own  interest  and  in  that  of  the 
patient,  avail  themselves  of  his  assistance.  Few 
things  can  be  more  damaging  to  a  practice  than 
for  a  patient  to  die  under  an  anaesthetic  in  a  dental 
chair,  and  it  is  not  too  much  to  say  that,  looking 
at  the  matter  from  the  lowest  and  merely  financial 
standpoint,  a  dental  practitioner  will  lose  more 
on  the  day  that  such  an  accident  happens,  from 
actual  damage  to  his  practice,  than  he  would  pay 
away  in  fees  to  a  medical  man  in  ten  years,  even 
were  he  to  do  it  all  out  of  his  own  pocket.  The 
question  is  a  very  difficult  one  to  deal  with,  as  is 
also  the  whole  question  of  the  relations  between 
the  dental  surgeon  and  the  family  doctor,  as 
regards  the  administration  of  anaesthetics.     Do 


THE  L.D.S.  DIPLOMA  233 

we  not  almost  weekly  see  in  the  medical  journals 
questions  asked  on  the  ethics  of  this  matter  ?  A 
patient  A.  has  a  medical  attendant  Dr.  B.,  and  on 
A.  going  to  consult  a  dentist  C.  he  tells  A.  that 
he  will  get  D.,  another  medical  man,  to  give  A. 
an  anaesthetic.  Dr.  B.  hears  of  the  matter,  and 
there  are  difficulties  and  heartburnings.  Now, 
the  proper  action  seems  to  be  this : 

When  a  patient  comes  for  the  first  time  to  a 
dental  surgeon  and  an  extraction  is  required,  it 
seems  to  be  the  right  thing  for  the  dentist  to 
communicate  with  the  patient's  own  doctor,  and 
ascertain  if  there  be  any  contra-indication  to  a 
general  anaesthetic,  or  any  constitutional  disability 
requiring  caution.  Having  done  this,  it  seems  to 
the  writer  that  the  dental  surgeon  is  entitled  to  ask 
whomsoever  he  pleases  to  give  the  anaesthetic.  If 
he  knows  the  doctor  not  to  be  very  skilled  in  anaes- 
thetic work,  he  naturally  will  choose  to  get  some- 
one in  whom  he  has  confidence,  and  with  whom  he 
is  accustomed  to  work,  in  his  own  and  the  patient's 
interest.  In  some  cases  the  patient  will  himself 
ask  that  his  ordinary  medical  attendant  may 
either  be  present  or  actually  administer  the 
anaesthetic,  and  in  such  a  case,  unless  he  have  the 
strongest  possible  reasons,  the  dentist  will  surely 
do  well  to  give  his  consent.  But  the  essential 
point  is  that,  if  an  anaesthesia  of  anything   but 


234  ANi^iSTHESIA  IN  DENTAL  SURGERY 

a  trifling  kind  be  undertaken,  an  intimation  be 
made  to  the  medical  attendant,  and  this  should 
especially  be  the  case  if  the  patient  is  at  the  time 
actually  under  his  treatment.  In  doing  this,  in 
the  vast  majority  of  cases  there  should  be  no  diffi- 
culty, either  by  note  or  telephone  message. 

If  it  be  impracticable  for  some  reason,  the 
optional  course  is  to  hand  the  administration  of 
the  anaesthetic  and  the  responsibility  for  the 
whole  matter  over  to  a  fully-qualified  and  expert 
medical  man,  who  will  examine  the  patient  and 
ascertain  any  particulars  as  to  the  physical  con- 
dition, and  take  such  precautions  as  are  necessary 
and  indicated  by  what  the  patient  tells  him. 

The  importance  of  this  matter  cannot  be  too 
much  emphasized.  By  communicating  with  the 
patient's  own  doctor,  the  dentist  is  treating 
him  with  courtesy,  and  in  a  way  which  he  will 
surely  not  be  slow  to  appreciate;  he  is  looking 
after  the  patient's  best  interests,  and  keeping 
himself  on  the  right  side. 

There  seems  to  be  no  question  that  the  casual 
administration  of  afty  anaesthetic  to  patients  who 
happen  to  drop  into  a  dentist's  surgery  without 
any  physical  examination,  and  without  any 
inquiries  as  to  their  general  health  or  physical 
ailments,  cannot  be  too  strongly  discouraged. 

It  is  quite  impossible  that  all  anaesthetics  can 


THE  L.D.S.  DIPLOMA  235 

be  administered  by  experts  or,  with  the  present 
state  of  the  Medical  Acts,  even  by  men  with  a 
medical  diploma,  but  there  seems  no  adequate 
reason  why  every  precaution  cannot  be  taken, 
and  with  the  person  who  neglects  to  take  them 
and  gets  into  trouble  we  have  little  sympathy 
when  he  meets  with  the  well-deserved  censure  of 
the  coroner  or  procurator-fiscal. 


APPENDIX 

A   SuMi^iARY  OF  Deaths  under  Nitrous  Oxide  Gas, 

COLLECTED    FROM    MaNY    SOURCES. 

Case  I. — January  22,  1873,  Exeter;  female,  set.  38; 
stout;  enlarged  tonsils  and  uvula;  dental  operation, 
semi-recumbent;  double  administration;  asphyxia. 

Case  2. — March  27,  1877,  Manchester;  male,  elderly; 
obese;  dental  operation ;  double  administration ;  asphyxia. 

Case  3. — September  15,  1883,  London;  male,  a;t.  57; 
tongue  enlarged  by  morbid  growths  and  fixed;  dental 
operation;  convulsive  tremor  and  rigidit^^;  asphyxia! 
syncope. 

Case  4, — 1885,  Paris;  male,  aet.  50;  dental  operation; 
'  syncope.' 

Case  5. — October  i,  1887,  Edinburgh;  female,  set.  71; 
stout;  corsets  tight;  food  in  stomach;  dental  operation; 
probably  '  asphyxia.' 

Case  6. — 1890,  Montreal;  male,  set.  24;  dental  opera- 
tion; '  syncope.' 

Case  7. — May  i,  1892,  Buffalo,  U.S.A.;  female, 
married;  dental  operation;  cause  uncertain. 

Case  8. — 1893,  Batley;  male,  aet.  39;  small,  deformed 
lower  jaw;  dental  operation;  asphyxia. 

Case  9. — 1893;  female;  dental  operation;  asph^^xia. 

Case  10. — Februar}^  21,  1894;  male,  set.  26;  enlarged 
tonsils,  receding  lower  jaw,  short  neck;  dental  operation; 
asphyxia. 

Case  II. — January,  1895,  Preston;  female,  aet.  23; 
tight  corsets;  full  stomach;  dental  operation;  asphyxia. 

Case  12. — October  7,  1895,  New  York;  female,  aet.  22; 
dental  operation. 

Case  13. — 1895,  Chestnut  Hill;  male;  dental  operation; 
asphyxia. 

236 


APPENDIX  237 

Case  14. — March,  1899,  Birmingham;  male,  aet.  12; 
large  abscess  in  base  of  tongue;  fixed  lower  jaw;  hori- 
zontal posture;  extension  of  head;  opening  of  abscess; 
asphyxia. 

Case  15. — Reported  in  1899,  London;  male,  set.  71; 
ver}^  delicate;  old  pericarditis  and  pleurisy;  dorsal 
posture ;  operation  for  adenoids  (NgO  and  air) ;  syncope ; 
no  respiratory  obstruction. 

Case  16. — June  15,  1899,  London;  female,  aet.  27; 
food  in  stomach;  operation  on  elbow;  double  adminis- 
tration; vomiting;  dusky  pallor;  '  syncope.' 

Case  17. — November,  1900;  male,  set.  36;  suppuration 
of  neck;  left  tonsil  swollen,  incision  of  neck  (NgO  first, 
then  with  air);  respiration  stopped;  asphyxia;  post- 
mortem, '  laryngeal  oedema.' 

Case  18. — December  20,  1902;  female,  set.  20;  abscess 
of  the  tonsil. 

Case  19. — In  1903,  Chelsea;  female,  set.  23  months; 
operation  for  adenoids;  '  spasm  of  the  glottis.' 

Case  20. — May,  1905,  at  Carlisle;  female,  set.  17;  dental 
extraction;  asphyxia;  unquahfied  dentist. 

In  addition  to  these  perfectly  authentic  cases,  there 
are  thirteen  others,  of  which  three  are  imperfectly  re- 
corded, and  the  remainder  occurred  in  such  a  way  as  to 
render  it  extremel}^  dubious  whether  the  anaesthetic  was 
to  blame  in  any  degree. 

Deaths  from  Somnoform  and  Ethyl  Chloride  which 
have  been  recorded  as  occurring  in  the  united 
Kingdom. 

Fatalities  under  Ethyl  Chloride. 
About  ten  years  ago  something  of  a  '  scare  '  was 
worked  up  over  ethyl  chloride,  and  some  well-known 
anaesthetists  practically  refused  to  administer  this  drug. 
While  one  cannot  altogether  understand  their  attitude, 
there  is  no  doubt  that,  in  unskilled  hands,  it  is  an  anaes- 


238   AN.^STHESIA  IN  DENTAL  SURGERY 

thetic  which  should  be  used  with  a  great  deal  of  caution, 
both  as  regards  dosage  and  length  of  administration. 

The  idea  had  got  about  among  a  large  number  of  both 
the  medical  and  dental  professions  that  ethyl  chloride 
was  a  sort  of  glorified  nitrous  oxide,  which  one  can  carry 
about  in  one's  waistcoat  pocket  and  administer  to  all 
and  sundry,  without  any  special  precaution  or  skill  on 
the  part  of  the  administrator. 

Nothing  farther  from  the  facts  of  the  case  could  be 
imagined,  and  the  somewhat  formidable  list  of  fatalities 
below  (in  view  of  the  youth  of  ethyl  chloride  as  a  general 
anaesthetic),  which  the  authors  have  been  at  some  pains  to 
get  together,  will,  they  trust,  go  far  to  check  the  indis- 
criminate use  of  the  drug.  Its  highly  toxic  character 
and  the  danger  due  to  the  great  rapidity  of  its  action 
should  be  fully  recognized,  as  well  as  its  admirable  pro- 
perties as  an  adjuvant  to  chloroform  and  ether.  There 
can  be  no  doubt  about  its  value  in  this  respect,  but  dis- 
crimination is  required  in  regard  to  its  use,  as  in  many 
things.  Beyond  one  or  two  cases  of  respiratory  arrest — 
when  the  authors  first  began  using  ethyl  chloride — they 
have  never  seen  any  trouble  from  it  in  an  experience  of 
some  two  thousand  cases,  but  they  early  recognized  the 
necessity  for  small  dosage,  and  great  care  and  watchful- 
ness in  its  administration. 

1.  Lotheisen's  case;  male,  aet.  41 ;  alcoholic  and  cardiac 
disease;  at  Innsbruck  [Munch.  Med.  Wochenschr.,  Novem- 
ber 18,  1900). 

2.  Bossart's  case;  child,  aet.  12  months;  suffering  from 
diphtheria;  at  Aaran  [Correspond. -Blatt  fiir  schweizer 
Aerzte,  October,  1902). 

3.  Olcott  Allen's  case;  male,  aet.  28;  operation  for 
hernia;  vomited  a  lot  of  fluid,  and  died  of  asphyxia 
[American  Journal  of  Medical  Science,  December,  1903). 

4.  Female;  suffering  from  advanced  dropsy;  at  Dublin 
[Lancet,  October  7,  1905). 


APPENDIX  239 

5.  Male;  suffering  from  swelling  in  the  neck  {Lancet, 
October  7,  1905). 

6.  Male;  abscess  in  jaw  {Lancet,  October  7,  1905)- 

7.  Male;  dental  case  {Lancet,  October  7,  1905)- 

8.  Male;  a  seaman  at  Haslar  Hospital;  dental  opera- 
tion {Portsmouth  Evening  News,  April  24,  1905). 

9.  Female,  set.  50;  at  Stourbridge  {British  Medical 
Journal,  July  8,  1905). 

10.  Female,  set.  40;  at  Eniield;  dental  case;  '  somno- 
form  '  was  used  {British  Journal  of  Dental  Science,  April, 
1904). 

11.  Female,  set.  42;  dental  case;  locality  unrecorded 
{British  Journal  of  Dental  Science,  April  i,  1904). 

12.  A  boy,  set.  10;  operated  on  for  adenoids  and 
tonsils  at  a  Plymouth  hospital  {General  Practitioner, 
August  19,  1905). 

13.  A  death  occurred  at  Llandudno  in  the  summer  of 
1903. 

14.  A  death  occurred  at  Swansea  in  1904  also  during 
a  dental  extraction. 

1 5 .  A  death  occurred  in  Edinburgh  in  J  uly ,  1 905 ,  during 
a  dental  operation,  patient  being  a  deUcate  woman  of 
50  years  of  age. 

16.  A  further  death  occurred  in  an  Edinburgh  hospital 
in  the  same  month  and  year. 

17.  Two  fatalities  occurred  in  Carlisle  in  1905. 

18.  A  death  occurred  in  London,  February,  1906,  in  a 
dentist's  chair. 

19.  A  death  occurred  at  a  Bradford  hospital  in  1906 
during  a  throat  operation. 

20.  In  January,  1906,  a  death  occurred  at  Oxford. 

21.  In  1905  a  death  occurred  at  Leeds;  and 

23  and  24.  Two  deaths  in  the  same  year  at  the  Mus- 
tapha  Civil  Hospital,  Algiers. 


INDEX 


Accessory  apparatus  required,  $8  et  seq. 
Accidents  connected  with  circulation,  218  et  seq. 
during  anaesthesia,  218  et  seq. 
treatment  of,  219  et  seq. 
with  respiration,  223 
Administration  of  chloroform  for  dental  work  condemned, 
119,  120 
of  ethyl  chloride,  87-90 

of  ethyl  chloride  and  ether,  146,  147,  154,  155 
of  '  gas  '  and  '  ether,'  160,  171 
of  nitrous  oxide,  64,  65,  66 
ethyl  chloride,  147,  148 
and  oxygen,  134  et  seq. 
(continuous),  69-78 
Adrenalin  and  cocaine,  iSo,  181 
Advantages  of  ethyl  chloride,  91,  92 

of  ethyl  chloride  and  nitrous  oxide  mixture  and  oxygen, 

159 
of  general  anaesthesia,  175,  176 
of  local  anaesthesia,  176 
of  nitrous  oxide  and  oxygen,  138,  139 
of  nitrous  oxide  by  Paterson's  method,  74 
^ther.     See  Ether. 
After-effects  of  chloroform,  120 
of  ether,  loi,  102 
of  ethyl  chloride,  89,  90 
of  nitrous  oxide,  68,  69 
and  oxygen,  138,  139 
Age  as  influencing  the  choice  of  the  anaesthetic,  27,  28,  29 

240 


INDEX  241 

Albuminuria  after  ethyl  chloride,  91 
Alcoholics,  the  administration  of  anaesthetics  to,  ^},  34 
Anaemia  patients,  92 
Anaesthesia,  accidents  of,  218  et  seq. 
dangers  of  chloroform,  119  et  seq. 
general,  advantages  of,  175 
history  of,  1-20 
local,  or  analgesia,  172  et  seq. 
advantages  of,  176 
disadvantages  of,  173 
pioneers  of,  i  et  seq. 
Anaesthetic  apparatus,  accessory,  ^8  et  seq. 
for  ethyl  chloride,  80,  81,  82 
for  the  administration  of  ether  and  ethyl  chloride,  154,  155 
of  nitrous  oxide,  48  et  seq. 
of  nitrous  oxide  and  ether,  160,  161 
of  nitrous  oxide  and  ethyl  chloride,  158,  159 
of  nitrous  oxide  and  oxygen,  129-150 
Paterson's  (for  nitrous  oxide),  71 
the  choice  of,  23 
Anaesthetics  in  alcoholism,  ^;^,  34 
in  advanced  years,  29 
in  cardiac  disease,  30 
in  childhood,  27 

in  hysterical  and  nervous  conditions,  32,  33 
in  patients  who  use  tobacco  to  excess,  34 

>vho  take  drugs,  t,^,  34 
in  pregnancy,  33 
in  pulmonary  conditions,  30 
x\naesthetist,  as  influencing  choice  of  anaesthetic,  26-27 
Analgesia  produced  by  means  of  cocaine,  178  et  seq. 
of  eucaine,  182 
of  stovaine,  184,  185 
of  tropa-cocaine,  184 
of  refrigeration,  210  et  seq. 
Artificial  respiration  (Sylvester),  220,  223 
Aryteno-epiglottidean  folds,  spasm  of,  227 
Asphyxia,  causes  and  symptoms  of,  223,  224 

treatment  of,  224,  225,  226 
Available  anaesthesia  under  various  anaesthetics,  26 

j6 


242     AN.ESTHESIA  IN  DENTAL  SURGERY 

Bag,  capacity  of  bag  in  N2O  inhaler,  54 

in  ethyl  chloride  inhaler,  capacity  of,  81 

in  gas  and  oxygen  apparatus,  with  septum,  134 

inhaler  necessary  for  ethyl  chloride,  8i 
Bib  or  apron,  38 
Blood  in  the  larynx,  treatment  of,  225,  226 

swallowing  of,  cause  of  sickness,  68 
Braine's  tongue  forceps,  36 
Bronchitis  as  a  result  of  ether  administration,  102 

care  required  in  cases  of,  29,  30 

Cardiac  failure  under  chloroform,  119,  122,  128 
Carter's  oral  net-spoon,  225 
Cases  of  death  under  chloroform,  118  et  seq. 
under  nitrous  oxide,  236,  237 
series  of  hundred  '  continuous  gas,'  76,  77 

of  fifty  NgO  and  ether,  i68,  169 
suitable  for  chloroform,  113,  114  et  seq. 
for  NgO  and  ether,  170,  171 
Causes  of  death  under  chloroform,  122,  123,  124 
Chemical  characters  of  ethyl  chloride,  79 

of  nitrous  oxide,  44,  45 
Children,  administration  of  anaesthetics  to,  27,  28 
Chloride  of  ethyl  (see  Ethyl  Chloride),  79 
Chloroform,  accidents  with,  121,  122,  123 
action  of,  on  circulation,  120,  123 
on  nervous  system,  122,  123 
on  respiratory  centre,   123 
on  vagus  nerve,  122 
asphyxial  compUcations  under,  123 
cardiac  inhibition  under,  122 
causes  of  circulatory  failure  under,  120,  122,  123 
causes  of  death  under,  122,  123 
compared  with  ether,  128 

discovery  of  anaesthetic  properties  of,  14,  15,  16 
failure  of  circulation  under,  122,  123,  124 

of  respiration  under,  123 
fatalities  under,  causes  of,  122,  123  "^ 

in  Scotland  and  England,  118 
heart  failure  under,  122,  123 


INDEX       ^  243 

Chloroform,  historical  sketch  of,  14,  15,  16,  17 
in  bronchial  and  pulmonary  ajiections,  30 
insanity  following,  31,  114 
laryngeal  spasm  under,  123 
objections  to,  in  dental  surgery,  119,  121 
place  in  dental  surgery,  116  et  seq. 
Professor  Coates'  conclusions  as  to,  122 
reflex  cardiac  inhibition  under,  122 
respiratory  failure  under,  123,  124 
sickness  following,  i  20 
summary  of  objections  to,  119 
syncope  under,  and  tieatment,  221 
Choice  of  the  anaesthetic,  23  et  seq. 

of  mouth-props,  37 
Circulation,  failure  of,  120,  121,  122 
under  chloroform,  120  et  seq. 
under  ethyl  chloride,  89 
under  nitrous  oxide,  62 
Clonic  muscular  spasm  under  nitrous  oxide,  63 
Clover,  J,  T.,  invention  of  ether  inhaler,  11 
Cocaine     hydrochlorate,     contra-indications    of,     in     dental 
surgery,  216 
and  adrenalin,  180,  181 
contra-indicated,  216 
dose  of,  179 

precautions  when  using,  179 
properties  of,  178 
strength  of  solutions  suitable,  179 
symptoms  of  over-dose,  179,  180 
treatment  of  cocaine  toxaemia,  iSo 
Colour  of  the  face  under  ether  and  nitrous  oxide,  164 
under  ethyl  chloride,  88 
under  nitrous  oxide,  64 
under  nitrous  oxide  and  oxygen,  148 
Comparison  of  chloroform  with  ether,  121,  128 

of  ethyl  chloride  with  other  auccsthetics,  92 
Compression  of   the   chest   as   restorative  in  syncopal  con- 
ditions, 222 
Conjunctival  reflex,  disappearance  of,  with  '  gas  and  ether,' 
165 


244    ANESTHESIA  IN  DENTAL  SURGERY 

Conjunctival  reflex  under  chloroform,  107 

^\'ith  nitrous  oxide,  64 
Continuous  administration  of  nitrous  oxide,  69  et  seq. 
advantages  and  disadvantages  of,  74,  75 
list  of  illustrative  cases  of,  76,  77 
Contra-indications   for   cocaine   and  local   anaesthetics,    174, 
175,  216 

for  ether,  30,  31,  7^^ 

for  refrigeration  methods,  215 
Cork  as  mouth-prop,  40 
Coughing  dtiring  the  induction  of  anaesthesia,  34,  2)5 

in  patients  who  use  tobacco  to  excess,  34,  25 
Croft's  gag,  39 
Cyanosis  absent  with  ethyl  chloride,  91 

and  asphyxia,  224 

in  '  tobacco  habit,'  35 

under  nitrous  oxide,  64 

under  nitrous  oxide  and  ether,  164 
Cylinders,  foot-keys  for,  51 

for  ethyl  chloride, 

for  nitrous  oxide,  51 

Danger  of  bronchitis  after  ether  grossly  exaggerated,  102 

of  cocaine-poisoning,  178,  179 

of  dentist  acting  as  both  anaesthetist  and  operator,  231 

of  pushing  nitrous  oxide  in  pregnancy,  33 

of  underestimating  toxicity  of  ethyl  chloride,  92 

of  using  chloroform  in  dental  work,  119,  120,  121 
Davy,  Sir  Humphry,  discoverer  of  nitrous  oxide,  3 
Death-rate  under  chloroform,  127,  128 

under  ether,  125 
Deaths  under  chloroform,  11^  et  seq. 

under  ether,  125 

under  ethyl  chloride,  237,  238,  239 

under  nitrous  oxide,  236,  237 
Degrees  of  nitrous  oxide  anaesthesia,  61,  62,  63 
Dental  extractions,  adjustment  of  mouth-prop  for,  40 

advantages  of  general  anaesthetic  for,  175,  176 

advantages  of  local  anaesthetic  for,  176 

chloroform  condemned  in  connection  with,  119,  120,  121 


INDEX  245 

Dental  extractions,  choice  of  anaesthetic  for.  23  e/  seq. 

choice  of  mouth-prop  for,  37,  38 

danger  of  tooth  faUing  into  larynx  during,  225,  226 

ethyl  chloride  for,  79  et  seq. 

ethyl  chloride  and  ether  for,  154,  155 

gas  and  ether,  160  et  seq. 

without  anaesthesia  in  children  barbarous,  43 
Directions     for     administration    of    chloroform,     104,     105 
et  seq. 

of  ethyl  chloride,  87,  88  et  seq. 

of  gas  and  ether,  162,  163 

of  nitrous  oxide,  60  et  seq. 

of  nitrous  oxide  and  oxygen,  129  et  seq. 
Disadvantages  of  chloroform  in  dental  surgery,  127,  128 

of  continuous  nitrous  oxide,  74,  75 

of  local  anaesthesia,  215,  216 

of  Paterson's  method  for  nitrous  oxide,  74,  75 
Discovery  of  chloroform  as  an  anaesthetic,  13,  14,  15 

of  cocaine,  178 

of  ether,  8,  9,  10 

of  ethyl  chloride,  17,  18,  19 

of  nitrous  oxide,  3,  4,  5 
Dose  of  ethyl  chloride,  81 

of  eucaine,  184 

of  tropa-cocaine,  184 
Duncan,  D.  Matthews,  13 
Duncan,  Mr.,  chemist,  14 

Effects  produced  by  chloride  of  ethyl,  89,  90,  91 

by  chloroform,  106,  107,  113,  120-125 

by  ether,  100,  102 

by  gas  and  ether,  164-167 

by  nitrous  oxide,  61,  62,  63,  64 

by  nitrous  oxide  and  oxygen,  137,  138 
Electric  battery  in  syncopal  conditions,  223 
Enema,  223 

Entry  of  foreign  body  into  air-passages,  225 
Epistaxis  caused  by  Harvey  Milliard's  nasal  tube,  70 
Erotic  ideas  induced  by  ethyl  chloride,  90 

induced  under  nitrous  oxide,  60 


246    AN.ESTHESIA  IN  DENTAL  SURGERY 

Ether,  bronchitis  after,  uncommon,  102 
contra-indications  to,  30,  33 
corneal  reflex  under,  165 

cougliing  under,  ^5,  99,  100 

discovery  of  anaesthetic  properties  of,  8,  9 
effects  on  the  circulation  of,  112,  113 

inflammability  of,  94 

nausea,  retching,  etc.,  after,  loi,  102 

pupils  under,  165 

sickness,  after,  loi,  102 
Ethyl  chloride,  administration  of,  88,  89 

after-effects  of,  89,  90  " 

albuminuria  after,  91 

anaesthesia,  duration  of,  89 

and  ether  sequence,  154,  155 

and  nitrous  oxide  compared,  92 

and  nitrous  oxide  sequence,  151,  152,  153 

as  a  local  refrigerant,  210,  211 

behaviour  of  alcohohcs  under,  24,  33 

chemical  characters  of,  79,  80 

discovery  of,  17,  18 

dose  of,  81 

erotic  ideas  under,  90 

fatalities  with,  237,  238 

general  conclusions  as  to,  91 

history  of,  17,  18,  19 

in  anaemic  patients,  92 

in  chronic  bronchitis,  30 

in  heart  disease,  31 

in  hysterical  subjects,  33 

in  patients  of  advanced  years,  29  , 

in  pregnancy,  33 

in  renal  disease,  91 

in  the  young,  28,  92 

inhalers  for,  80,  81  et  seq. 

jaundice  as  a  sequela  of,  91 

length  o^  anaesthesia  under,  88 

lint  in  inhalers  for,  undesirable,  84 

masseteric  spasm  under,  88 
posture  of  patient  for,  87 


INDEX  247 

Ethyl  chloride,  preparation  of  patient  for,  86 

sickness  frequent  after,  90,  92 

time  occupied  in  induction  of  anaesthesia  by,  88 

toxicity  not  properly  estimated,  93 
Eucaine,  advantages  of,  182,  183,  184 

cheapness,  183 

dose  of,  184 

how  to  make  solutions  of,  183 

safety  of,  182 
Evans,  Dr.,  and  the  introduction  of  nitrons  oxide,  7 

Failure  of  circulation,  219,  220,  221 

of  Morton  to  patent  ether,  10 

of  respiration,  127,  12S 
Faintness  after  ethyl  chloride,  91 

after  nitrous  oxide,  69 

after  nitrous  oxide  and  oxygen,  138 
Falling  back  of  the  tongue,  124 
Faradism  in  syncopic  conditions,  223 
Fatalities  under  chloroform,  causes  of,  118  et  seq. 

under  chloroform.  Dr.  Hewitt's  tables  of,  118,  119 

under  cocaine,  180 

under  ether,  124,  125  et  seq. 

under  ethyl  chloride,  237,  238 

under  nitrous  oxide,  236,  237 
Factors  influencing  choice  of  the  anaesthetic,  23 

(a)  the  patient,  23 

(6)  the  operation,  25 

(c)  the  operator,  25 

{d)  the  anaesthetist,  26, 
Ferguson's  gag,  36 

First  use  of  ether  in  general  surgery,  9 
Food,  abstinence  from,  prior  to  ethyl  chloride,  86 

prior  to  nitrous  oxide,  58 
Foreign  bodies  in  the  larynx,  224,  225,  226 

Gag,  Croft's,  39 

Dudley  Buxton's,  38 
Ferguson's,  36 


248     ANAESTHESIA  IN  DENTAL  SURGERY 

Gag,  spring,  39 

Gas  and  ether  administration,  160,  161,  162 

apparatus,  161 

corneal  reflex  under,  165 

cyanosis  under,  164 

deep  anaesthesia  under,  167 

dilated  pupils  under,  167 

duration  of  anaesthesia  under,  167,  168 

lor  alcoholic  patients,  24,  165 

for  anaemic  patients,  165 

for  hysterical  patients,  24 

for  patients  who  use  tobacco  to  excess,  34,  35 

Guy's  methods  in  connection  with,  162,  166-170 

pupils  under,  165 

signs  of  anaesthesia,  164,  165 
Gas  and  oxygen,  administration  of,  129-150 

administered  by  Paterson's  apparatus,  72,  73 

advantages  of,  74 

after-effects  of,  74 

apparatus  for,  72,  73 

disadvantages  of,  74 
unsuitable  for  children,  74 

available  anaesthesia  under,  71 

for  old  people,  29 

for  phthisical  patients,  30,  31 

Hewitt's  apparatus  for,  132-140 

pallor  and  feeble  pulse  under,  69 

period  required  for  induction  of  anaesthesia  by,  72 
Gas,  recovery  of  consciousness,  66,  67 
Gasometer,  52 

advantages  and  disadvantages,  52,  ^2 
Guy  on  the  choice  of  the  anaesthetic,  23  g/  seq. 
Guy's  ethyl  chloride  inhaler,  152 
and  ether  inhaler,  106 

Heart  disease,  anaesthetics  in,  30 

careful  examination  of  pulse  in,  30 
Heart,  effects  of  chloroform  on,  120,  121,  122 

of  cocaine  on,  179,  180 

of  ethyl  chloride  on,  91,  93 


INDEX  240 

Heart,  effects  of  nitrous  oxide  on,  63 

Heart  failure  under  chloroform,  iig  et  seq. 

Heister's  mouth  wedge,  36 

Hewitt's,  Dr.  F.  W,,  gas  and  oxygen  apparatus,  132,  140 

list  of  chloroform  fatalities,  118 

mouth-prop,  38 

paper  on  death-rate  from  chloroform  in  Scotland,  117 
History  of  anaesthetics,  i  et  seq. 

of  chloroform,  12,  13,  14 

of  ether,  7,  8,  9,  10 

of  ethyl  chloride,  17,  iS,  19 

of  nitrous  oxide,  3,  4,  5,  6 
Hysterical  patients,  32 

Impurities  in  nitrous  oxide,  45 
Indications  for  cocaine,  215  et  seq. 

for  freezing,  216,  217  ^ 

Induction  of  anaesthesia,  time  required  for: 

(i)  with  ethyl  chloride,  88 

(2)  with  nitrous  oxide,  67 

(3)  with  nitrous  oxide  and  oxygen,  137  et  seq. 
Infiltration,  technique  of  anaesthesia  by,  188 
Inflammable  nature  of  ether,  94 

Inhaler,  Clover's  ether,  11,  95,  161,  166 

Guy's  ethyl  chloride,  152 

ethyl  chloride  and  ether,  154 

ethyl  chloride  and  nitrous  oxide,  152 

Hewitt's  gas  and  oxygen,  135 

nitrous  oxide,  53 

nitrous  oxide  and  ether,  161 
Inhibition,  vagus,  under  chloroform,  119 
Injection  of  cocaine  to  produce  local  anaesthesia,  179 

how  to  make  the,  192  et  seq. 
Insanity  following  the  inhalation  of  anaesthesia,  32 
Insertion  of  the  mouth-prop,  40 
Introduction  of  chloroform,  13,  14,  15 

of  cocaine,  178 

of  ethyl  chloride,  17,  18,  19 

of  ether,  7-10  • 

of  nitrous  oxide,  4-6 


250    AN.ESTHESIA  IN  DENTAL  SURGERY 

Jactitation  under  nitrous  oxide,  63 
Jaundice  after  ethyl  chloride,  91 

Keith,  Dr.  George,  13 

Laryngeal  stertor  under  chloroform,  124 

Laryngotomy  in  asphyxia,  226 

Laughing-gas  (see  Nitrous  Oxide),  43 

L.D.S.  diploma  and  the  administration  of  anaesthetics,  229, 

238 
Light  anaesthesia  of  chloroform  dangerous,  126 
Lip  rubbing  as  a  stimulant  to  the  heart  and  circulation,  223 
Lividity  under  gas  and  ether,  164 
Local  anaesthesia  induced : 
by  eucaine,  182 
by  a  and  ^  eucaine,  2  per  cent,  solution,  182,  183 

advantages  of,  181,  182 
by  cocaine  hydrochlorate,  178  et  seq. 
dangers  of,  179,  180 
dose  of,  179 
properties  of,  178,  179 
toxic  symptoms,  179,  180 
treatment  of,  180 
by  freezing,  with  coryl,  217 
with  ethyl  chloride,  212 
with  methyl  chloride,  211 
by  stovaine,  advantage  as  regards  safety,  185 
discovery  by  Fourneau,  185 
strength  of  solution  used,  185 
toxicity  of  cocaine  greater,  185 
vaso-dilator  action  of,  185 
by  tropa- cocaine,  184 
advantages  of,  184 
dose  of,  184 
eucaine,  cheapness  of,  as  compared  with  cocaine,  183 

dose  of,  184 
pain  caused  by  freezing,  214 
sloughing  after  freezing,  211 
syringe  for  use  in  j)roducing  local  anaesthesia,  189 

sterilization  of,  191,  192 
technique  of  infiltration  methods,  188,  189 


INDEX  251 

McCardie's  work  in  connection  with  ethyl  chloride,  18,  19 
Medullary  centres,  action  of  chloroform  on,  122 
Method  of  application  of  ethyl  chloride  locally,  212,  213 
Micturition,  in  children,  under  nitrous  oxide,  64 
Morton,  W.  T.  G.,  a  pioneer  of  anaesthesia,  i,  9,  10 

discovery  of  anaesthetic  properties  of  ether  by,  9,  10 

failure  of,  to  patent  ether,  11 
Mouth-opener,  Heister's,  36 
Mouth-prop,  Buck's,  39;  Hewitt's,  37 
Muscular  relaxation  under  ethyl  chloride,  88  • 

Myocardium,  action  of  chloroform  on,  123 

Nausea  and  vomiting  after  chloroform,  120 
after  ether,  loi 
after  ethyl  chloride,  89,  90 
after  nitrous  oxide,  69 
and  oxygen,  138 
Nervous  children  frightened  by  apparatus,  28 

unsuited  for  local  anaesthesia,  173 
Nervous  disorders,  choice  of  anaesthetic  in,  32 
Neurotic  subjects,  33 

Nitrous  oxide,  administration  of,  64,  65,  66 
to  the  aged,  29 

advantages  of  nasal  method  for,  74 

after-effects  of,  68,  69 

and  oxygen,  138 

apparatus  for  administration  of,  132  et  seq. 

available  anaesthesia  afforded  by,  67,  68 

blood  changes  under,  46,  47,  48 

blood-pressure  under,  48,  iii,  112 

change  of  colour  under,  62,  63,  64 

chemical  and  physical  characters,  44,  45 

circulation  under,  47,  63 

clonic  spasm  under,  63 

conjunctival  reflex  under,  62,  64 

continuous  administration  of,  69  et  seq. 

cyanosis  under,  64 

cylinders  for,  48 

dangers  connected  with  administration,  224,  225 

discovery  of,  4,  5,  6 


f 

/  ■ 

/ 

/ 

252    AN^STHESIA-m  DENTAL  SURGERY 

Nitrous  oxide,  distortion  of  features  under,  63,  64 

dreams  under,  62 

effect  on  brain  and  spinal  cord,  47 

gasometer  for,  52 

impurities,  45 

in  heart  disease,  30,  31 

in  old  age,  29 

in  pregnancy,  2>Z 

in  pulmonary  disease,  30 

jactitation  under,  63 

micturition  in  children  under,  64 

muscular  system  xmder,  63 

nasal  method  of  administration,  69,  70,  71,  72 

Paterson's  apparatus  for,  72,  73 

physiological  action  of,  46,  47,  48 

preparation  of  the  patient  for,  58,  59,  60 

properties  of,  44,  45 

pulse  under,  63 

respiration  under,  62 

rotation  of  the  eyeballs  under,  64 

spasm  of  muscles  under,  63 

stages  in  the  administration  of,  61,  62,  63,  64 

stertorous  breathing  under,  63 

twitching  of  eyelids  under,  63 
Number  of  punctures  necessary  in  injecting  cocaine  into  gum, 
207,  208,  209 

Objections  to  chloroform  in  dental  surgery,  118,  119,  120 
Oxygen  and  nitrous  oxide,  129  et  seq. 

Paterson's  apparatus  for  nitrous  oxide,  71,  72 
Patients  in  advanced  years,  29 

who  use  alcohol  to  excess,  24,  33 

tobacco  to  excess,  34 
Physiological  action  of  nitrous  oxide,  46,  47,  48 
Pioneers  of  anaesthesia,  i  et  seq. 
Points  in  a  mouth-prop,  40 
Position  of  patient  for  chloroform,  115 

for  ethyl  chloride,  87 

for  nitrous  oxide,  60 
prone,  after  cocaine,  180 


INDEX  253 

Precautions  necessary  in  pulmonary  patients,  30,  31 

when  injecting  cocaine,  178,  191,  192 

with  chloroform,  ii  used,  104,  115 

with  cocaine,  191,  192 

with  ethyl  chloride,  91,  92,  93 

with  gas  and  ether,  162  et  seq. 
Pregnancy,  as  influencing  choice  of  anaesthetic,  t,2> 
Preparation  of  the  patient  for  ethyl  chloride,  86 

for  nitrous  oxide,  58,  59 
Priestley,  Joseph,  3 
Production  of  local  aneesthesia  by  injection  of  drugs,  177  ei  seq . 

by  freezing,  210,  211 
Pulmonary  patients,  administration  of  anaesthetics  to,  30,  31 
Pulse  under  chloroform,  120,  124 

under  ether,  112 

under  ethyl  chloride,  88 

under  nitrous  oxide,  63 

under  overdose  of  cocaine,  180 
Pupils  under  ethyl  chloride,  87 

under  nitrous  oxide,  64 

under  nitrous  oxide  and  ether,  64,  167 

Readministration  of  gas,  69 

of  ethyl  chloride,  91 
Rebreathing,  84,  85,  86,  163,  164 
Recovery  of  consciousness,  66 

Recumbent  position  when  inhaling  chloroform,  120 
Reflex  stimulation  of  the  vagus,  danger  of,  122 
Relative  safety  of  chloroform  and  ether,  126,  127 
Respiration  under  chloroform,  failure  of,  122,  123 

under  ethyl  chloride,  89 

under  nitrous  oxide,  60,  61 

obstruction  of,  223,  224 
Riggs,  John,  5 
Rigidity  of  the  muscular  system,  64 

Safety,  relative,  of  anaesthetics,  126,  127 

of  ethyl  chloride  and  nitrous  oxide,  92 
Schimmel's  needles  for  cocaine  syringe,  190 
Sickness  after  chloroform,  120 


254    AN.ESTHESIA  IN  DENTAL  SURGERY 

Sickness  after  ethyl  chloride,  90,  92 

alter  ether,  loi,  102 

after  nitrons  oxide,  69 
Signs  of  anaesthesia  with  ethyl  chloride,  Si,  89 

with  nitrous  oxide,  61 
and  ether,  loi",  165 
Simpson,  Sir  J.  T.,  and  the  introduction  of  chloroform,  12,  13 

14 

Somnoform,  18 

Spasm  of  glottis,  225 

Sterilization  of  syringe  for  local  anaesthetics,  191,  192 

Stovaine,  advantages  of,  185 

strength  of  solution  to  use,  185 

toxicity  of  cocaine  greater  than,  185 

used  in  sitting  posture,  185 

vaso-dilator  action  of,  185 
Syncope  under  chloroform,  120,  121,  122 

symptoms  of,  219 

treatment  of,  220 
Syringe  for  local  anaesthetics,  description  of,  189 

Table  of  100  '  continuous  gas  '  cases,  76,  77 

of  50  gas  and  ether  cases,  168,  169 

of  chloroform  fatalities,  118,  119  etseq. 
Technique  of  local  anaesthesia  by  infiltration,  188  el  scq. 
Third  person  necessary  in  operating-room,  Co,  90 
Time    taken  in  induction    of    anaesthesia  with  cocaine,    60, 
90,  201 

with  ethyl  chloride,  88 

with  nitrous  oxide,  67,  68 
and  oxygen,  137 
Tobacco  habit,  34,  7,^ 
Tongue  faUing  back,  124 

traction  in  laryngeal  spasm,  227 
Trachea,  entry  of  blood  into,  226,  227 

treatment  of,  227 
Tracheotomy  for  foreign  bodies  in  trachea,  226 
Tropa-cocaine : 

advantages  of,  184 

dose  of,  184 


INDEX  255 

Vagus  inhibition  under  chloroform,  122 
Vaso-dilator  action  of  stovaine,  185 
Vaso-motor  paralysis  under  chloroform,  121,  123 
Vomiting  after  chloroform,  120 

after  ether,  loi 

after  ethyl  chloride,  89,  90 

after  nitrous  oxide,  69 

Waldie,  D.,  13 

Warren,  J.  C,  9 

Water,  hot,  enema  for  restorative  purposes,  223 

Wedge,  Heister's  mouth-,  36 

Wells,  Horace,  i,  5,  6,  7 

discovery  of  anaesthetic  properties  of  nitrous  oxide,  5 

suicide  of,  6 


THE    END 


BILLING    AND    SOtIS,   LTD.,    PKIKTEKS,    GUILDFORD,    ENGLAND 


PRESS  NOTICES  OF  PREVIOUS  EDITIONS 

British  Medical  Journal. — '  Our  opinion  stands  on  record 
and  still  holds  that  this  is  an  excellent  little  book,  which  we 
confidently  recommend  to  all  interested  in  the  subject.  The 
third  edition  has  been  revised.' 

Lancet. — The  book  maintains  its  former  character  a^  a 
clear  account  of  the  practice  of  anaesthetics  in  connection 
with  dental  surgery.  Dr.  Luke  is  to  be  congratulated  on  the 
appearance  of  a  third  edition — an  evidence  of  the  success 
wliich  the  concise  and  practical  character  of  his  manual  has 
earned  and  fully  deserves.' 

Dublin  Medical  Journal.—'  The  author  has  offered  us 
matter  which  is  comprehensive,  readily  grasped,  pithy,  and  up 
to  date.  There  lies  within  these  pages  much,  if  not  all,  which 
a  dentist  or  dental  anaesthetist  need  know  of  anaesthetics.  We 
can  readily  concur  with  almost  all  the  conclusions  arrived  at. 
The  book  is  to  be  recommended  to  the  notice  of  all  interested 
in  the  subject.     It  is  a  book  sui  generis,  and  a  success.' 

The  Dental  Record. — '  The  aim  of  the  author  of  this  book 
has  been  to  pass  the  various  anaesthetics  and  combinations 
used  in  operative  dentistry  before  the  reader's  eye  with  a  brief 
description  of  the  properties  of  some  of  them,  the  method  of 
application,  advantages  and  disadvantages.  This  aim  the 
author  has  carried  out  with  success.  The  matter  is  placed 
before  the  reader  in  a  pleasant  manner,  and  we  have  no 
hesitation  in  recommending  the  book  to  the  notice  of  the 
profession.' 

Boston  Medical  and  Surgical  Journal. — '  This  little  book 
furnishes  so  much  accurate  information  that  it  will,  in  many 
cases,  serve  in  lieu  of  experience.  The  description  of  the 
apparatus  is  clear  and  sufficient.  The  comparative  values  of 
the  various  anaesthetics  are  well  drawn.  The  book  is  essential 
to  the  young  dentist,  while  the  older  man  in  the  profession  will 
find  many  suggestions  which  will  enable  him  to  improve  his 
practice.' 

Ash's  Quarterly  Circular.—'  One  of  the  most  pleasing 
features  about  this  book  is  the  bold  and  vigorous  manner  in 
which  the  author  condemns  the  use  of  chloroform  in  dental 
operations,  and  in  our  opinion  he  deserves  to  be  warmly  con- 
gratulated for  so  fearlessly  expressing  his  views  as  to  the 
dangers  attending  its  employment.  The  book  is  pleasantly 
written,  contains  much  useful  information,  and  will  be  very 
serviceable,  not  only  to  the  dental  student,  but  also  to  those 
general  practitioners  who  administer  anaesthetics  for  dentists.' 


1 

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